Combustion systems and methods

ABSTRACT

Embodiments disclosed herein relate to internal combustion engines, combustion systems that include such internal combustion engines, and controls for controlling operation of the combustion engine. The internal combustion engine may include one or more mechanisms for injecting fuel, air, fuel-air mixture, or combinations thereof directly into one or more cylinders, and controls may operate or direct operation of such mechanisms.

This application claims priority to U.S. Provisional Application No.62/529,462 filed on 6 Jul. 2017, the disclosure of which is incorporatedherein, in its entirety, by this reference.

BACKGROUND

This disclosure relates to an internal combustion engine that mayoperate on gaseous fuel, liquid fuel, solid fuel, or combinationsthereof.

Generally, internal combustion engines may have any number ofconfigurations and sizes. For instance, an internal combustion enginemay have various piston layouts, such as in-line, flat (also known asboxer), and V configurations. Also, an internal combustion engine mayhave a rotary configuration. Improving construction and/or operation ofthe internal combustion engine may lead to improved or more efficientoperation, improved useful life, reduced operating costs, etc.

Accordingly, users and manufacturers of internal combustion enginescontinue to seek improvements thereof.

SUMMARY

Embodiments described herein are directed to an internal combustionengine that includes at least one combustion chamber, output shaft, andenergy conversion mechanism for converting the energy produced duringcombustion of a fuel into mechanical output at the output shaft (e.g.,converting pressure increase in the combustion chamber into rotation ofthe output shaft). In an embodiment, the fuel and oxidizer are injectedinto the combustion chamber and a combustion reaction produces apressure increase therein; the engine may include one or more energyconversion mechanisms configured to convert the increased pressure inthe combustion chamber into mechanical energy, such as rotation of theoutput shaft.

In an embodiment, a combustion system includes an engine and acontroller operably coupled to the engine. The engine includes one ormore combustion chambers each of which includes one or more injectionports and an exhaust port. The engine also includes one or moreinjectors each of which is in communication with a corresponding one ofthe one or more injection ports. Each of the one or more injectors isconfigured to inject at least an amount of air into a corresponding oneof the one or more combustion chambers for a combustion reaction thatproduces a pressure increase within the corresponding one of the one ormore combustion chambers. The engine also includes one or more energyconversion mechanisms each of which is positioned within in acorresponding one of the one or more combustion chambers and configuredto convert the pressure increase in the corresponding one of the one ormore combustion chambers into mechanical energy. The engine alsoincludes an output shaft configured to move in response to themechanical energy generated by the one or more energy conversionmechanisms. The engine also includes at least one exhaust valve incommunication with the exhaust port of each of the one or morecombustion chambers. The engine is devoid of at least one of a throttlebody, a retainer, a cam lobe, a cam shaft, a timing belt, or a shim. Thecontroller is configured to determine the amount of the air, at leastpartially based on one or more inputs received by the controller, toinject into at least one combustion chamber of the one or morecombustion chambers through the one or more injectors in communicationwith the at least one combustion chamber. The controller also isconfigured to actuate the one or more injectors in communication withthe at least one combustion chamber to inject at least the amount of airinto the at least one combustion chamber.

In another embodiment, a method of controlling combustion of acombustion engine is disclosed. The method includes, with a controlleroperably coupled to the combustion engine, receiving one or more inputsrelating to an operating parameter of the combustion engine. The methodalso includes, with the controller, determining, at least partiallybased on the one or more inputs, at least an amount of air to injectinto at least some of one or more combustion chambers in the combustionengine through at least one injector associated with at least oneinjection port of the combustion chamber, the combustion engine beingdevoid of a throttle body, a retainer, a cam lobe, a cam shaft, a timingbelt, or a shim. The method also includes, with the controller,actuating the at least one injector of the at least some of the one ormore combustion chambers to inject at least the amount of air determinedfor the at least some of the one or more combustion chambers.

Features from any of the disclosed embodiments may be used incombination with one another, without limitation. In addition, otherfeatures and advantages of the present disclosure will become apparentto those of ordinary skill in the art through consideration of thefollowing detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate several embodiments, wherein identical referencenumerals refer to identical or similar elements or features in differentviews or embodiments shown in the drawings.

FIG. 1 is a front isometric view of an internal combustion engineaccording to an embodiment;

FIG. 2 is a side view of the internal combustion engine of FIG. 1;

FIG. 3 is a back isometric view of the internal combustion engine ofFIG. 1;

FIG. 4 is a partial longitudinal cross-sectional view of the internalcombustion engine of FIG. 1;

FIG. 5 is a partial transverse cross-sectional view of the internalcombustion engine of FIG. 1;

FIG. 6 is a schematic block diagram of a fuel system according to anembodiment;

FIG. 7 is a schematic block diagram of a fuel system according toanother embodiment;

FIG. 8 is a schematic block diagram of an air system according to anembodiment;

FIG. 9 is a flow chart of a method of controlling operation of aninternal combustion engine according to an embodiment;

FIG. 10 is a flow chart of a method of controlling operation of aninternal combustion engine according to another embodiment;

FIG. 11 is a flow chart of a method of controlling operation of aninternal combustion engine according to yet another embodiment;

FIG. 12 is a partial cross-sectional view of a cylinder of an internalcombustion engine, according to an embodiment; and

FIG. 13 is a block diagram of a controller according to an embodiment.

DETAILED DESCRIPTION

Embodiments described herein are directed to an internal combustionengine that includes at least one combustion chamber, output shaft, andenergy conversion mechanism for converting the energy produced duringcombustion of a fuel into mechanical output at the output shaft (e.g.,converting pressure increase in the combustion chamber into rotation ofthe output shaft). In an embodiment, the fuel and oxidizer are injectedinto the combustion chamber and a combustion reaction produces apressure increase therein; the engine may include one or more energyconversion mechanisms configured to convert the increased pressure inthe combustion chamber into mechanical energy, such as rotation of theoutput shaft.

Generally, the combustion chamber and/or the energy conversion mechanismmay vary from one embodiment to the next. For instance, the internalcombustion engine may include one or more cylinders and correspondingpistons that may define or form the combustion chamber thereof. Theenergy conversion mechanism may include the pistons movable in thecylinders in response to combustion of a fuel and air mixture. Thepistons may be rotatably mounted on the output shaft (e.g., on acrankshaft), such that linear/reciprocating movement thereof (e.g., in atwo- or four-stroke cycle) may be converted to rotation of thecrankshaft. Alternatively or additionally, the engine may include alinear output mechanism that may be moved linearly and/or mayreciprocate in response to combustion and/or pressure increase in thecombustion chamber.

Additionally or alternatively, the internal combustion engine may be arotary engine (e.g., Wankel engine, etc.) and may include a combustionchamber at least in part formed or defined non-reciprocatingmechanism(s) that may convert the energy produced during combustion intorotation of the output shaft. For example, the combustion chamber of theengine may be formed or defined by and between rotor and housing (e.g.,for a Wankel engine). Hence, for instance, the energy conversionmechanism may include a rotor that may rotate an output shaft inresponse to a pressure increase produced in the housing during and/orafter combustion of fuel.

In some instances, in a four-stroke cycle of a reciprocating internalcombustion engine that includes one or more pistons, air and fuel may beenter an upper end of the cylinder by the descending piston and may becompressed as the pistons rise during their upward stroke. The mixtureis ignited and combusted in the cylinder, which forces the pistons tocommence their next downward stroke. The final upward stroke expels thegases resulting from combustion, and thereafter the next suction strokecommences. Generally, air enters the combustion chamber of the enginethrough one or more intake valves that may open during the down strokeof the piston. Furthermore, the fuel is delivered into the cylinder, andafter the intake valves close, the cycle above-described commences.

In a conventional engine, each cylinder may have at least one fuel-airintake port controlled by an intake valve and at least one exhaust portfor exhaust gas, which also may be controlled by an exhaust valve. Someconventional engines may have two or more intake valves and/or two ormore exhaust valves. Generally, the intake and/or exhaust valves may beopened and closed at precise times during the engine's cycle, which mayinvolve complex timing connections (e.g., belts, chains, etc.) and camsthat may actuate the intake and/or exhaust valves. For example, a timingbelt may connect engine's crankshaft to a cam shaft that may open andclose intake and/or exhaust valves based on the rotation of thecrankshaft and positions of pistons in corresponding cylinders (i.e.,timing the piston positions to the intake and exhaust valve openings andclosings). Some conventional engines may include electronicallycontrolled and/or operated intake and/or exhaust valves.

In some instances, a conventional engine may have a Gasoline DirectInjection (GDI) system in which a fuel injector may feed fuel directlyinto the cylinder. Conventional engines with the GDI systems may includeintake valves (e.g., poppet or stem valves), which may open for airintake, and exhaust valves, which may open for gas exhaust. Hence, suchengines may have a timing mechanism and a cam shaft to time opening andclosing of the intake and exhaust valves during the engine's cycle.

Generally, as mentioned above, the internal combustion engine accordingto one or more embodiments described herein includes one or morecombustion chambers (e.g., the internal combustion engine may have oneor more cylinders that may include combustion chambers and may bearranged in any suitable manner and may have any suitable size). In anembodiment, the combustion system includes one or more mechanisms forinjecting fuel, air, fuel-air mixture, or combinations thereof into oneor more combustion chambers of the internal combustion engine (e.g.,into cylinders, combustion chamber(s) of a rotary engine, such a Wankelengine, etc.). Additionally, in some examples, quantities of theinjected fuel, air, fuel-air mixture, or combinations thereof may byaccurately measured and/or controlled as well as adjusted duringoperation of the internal combustion engine. While references herein aremade generally to “air,” it should be appreciated that any suitableoxidant may be mixed with fuel and/or injected into the cylinders (e.g.,oxygen (02)).

Moreover, in some embodiments, reducing moving parts in the internalcombustion engine (as compared with a conventional combustion engine)may reduce mechanical losses during operation (e.g., losses resultingfrom friction of various components), reduce the weight of the internalcombustion engine, and/or otherwise improve efficiency thereof. Forexample, in some embodiments, the internal combustion engine is devoidof at least one or more of a throttle body, a retainer, a cam lobe, acam shaft, a timing belt, a shim, the air intake valve on the cylinderof the engine, or the air intake port. Additionally or alternatively, inat least one embodiment, the internal combustion engine may be simpleror less expensive to fabricate and/or maintain during operation.

In an embodiment, the internal combustion engine includes one or morefuel injectors to inject fuel directly into the combustion chamber(s)(e.g., into the cylinders). Moreover, in some embodiments, the internalcombustion engine includes one or more air injectors that may inject airdirectly into the combustion chamber(s) (e.g., into the cylinders of theinternal combustion engine). For example, in contrast to theconventional engine, the internal combustion engine described herein mayhave no intake valves for opening and/or closing air flow into thecombustion chamber(s). Accordingly, in some embodiments, each and everyair port in the internal combustion engine is coupled to a correspondingair injector, such as the air injection port. In such embodiments, noadditional air ports beyond the air injection port on the cylinder arerequired, as there are no air intake valves for enabling drawing ambientair into the combustion chamber via an intake stroke of a piston in thecombustion chamber. For example, each of the one or more injectors isconfigured to inject at least an amount of air or other oxidizer intothe corresponding one of the one or more combustion chambers for thecombustion reaction without the aid of air provided by an air intakestroke from the engine.

According to one or more embodiments, air injectors may be operatedindependently of the state of the combustion chamber (e.g., independentof piston positions and/or rotation of the crankshaft). For example,during some portions of the combustion cycle, the internal combustionengine may compress fuel and/or air in the combustion chamber (e.g.,during an upstroke of the pistons). In other words, the air, fuel,fuel-air mixture may be injected into the combustion chamber at any timeduring the combustion cycle (e.g., when the piston is located at anysuitable position in the cylinder).

In an embodiment, the internal combustion engine includes one or moreexhaust ports for exhausting combusted gasses from the combustionchamber. Under some operating conditions, the exhaust ports may operateindependently of the rotation of the output shaft (e.g., independent ofthe rotation of the crankshaft and/or reciprocation of piston locationin the cylinder(s)). For example, one, some, or each of the cylindersmay include a dedicated exhaust port, and an exhaust valve (e.g.,electromechanical valve) may control the flow of exhaust gases from thecorresponding cylinder(s) through the exhaust port(s).

In at least one example, one, some, or each of the cylinders of theinternal combustion engine include a fuel injection port, an airinjection port, and an exhaust port, each of which is in fluidcommunication with the respective cylinders. More specifically, fuel maybe injected into the cylinder through the fuel injection port, air maybe injected into the cylinder through the air injection port, andexhaust gas may exit the cylinder through the exhaust port. As mentionedabove, valves controlling fuel injection, air injection, and gas exhaustat corresponding ports may operate independently of one another.Furthermore, the amount of air and/or fuel injected into the combustionchamber may be determined and/or preset prior to injection thereof.

For instance, the one or more valves or injectors at the air injectionports may open for a selected (e.g., calculated) and/or predeterminedamount of time to inject a selected (e.g., calculated) and/orpredetermined amount of air into the cylinder (e.g., the valves may beelectrically or electromagnetically operated, hydraulically operated,etc.). In some embodiments, one, some, or all of the cylinders of theinternal combustion engine may have multiple fuel injection ports,multiple air injection ports, multiple exhaust ports, or combinationsthereof.

As mentioned above in some embodiments, the internal combustion engineincludes reciprocating pistons that reciprocate in the correspondingcylinders during the combustion cycle. Generally, reciprocating movementof the pistons in the cylinders may produce rotation of the crankshaft.Hence, number of rotations per minute (RPM) of the crankshaft may beproportionate to the number of reciprocations of pistons or cycles inone, some, or all of the cylinders of the engine. In a conventionalengine, opening and/or closing of spring-loaded valves may limit thefrequency of piston's cycles in a cylinder (e.g., as the frequency ofvalve openings increases, the springs closing the valves may be unableto close the valve in a suitable amount of time and/or the valves maybecome unseated); this may in turn limit the operating range of RPM forthe conventional engine. By contrast, however, it should be appreciatedthat the internal combustion engine described herein may operate at anysuitable range of RPM. For instance, direct injection of air into thecylinders (and absence of the valves and springs) in the internalcombustion engine may facilitate operation of the engine at higher RPM(as compared with a conventional engine (e.g., with similar number ofcylinders and/or displacement)).

FIG. 1 is a front isometric view of an internal combustion engine 10according to an embodiment. In the illustrated embodiment, the engine 10includes a block 12 that has six in-line cylinders arranged in astraight line, which at least partially define combustion chambers ofthe engine 10. It should be appreciated, however, that the engine mayhave any number of cylinders and any number of suitable cylinderarrangements, as discussed above (e.g., V, rotary, boxer, etc.).

As described above, the engine 10, generally, includes combustionchamber, a mechanism for combusting the fuel therein, and a mechanismfor converting the energy produced during combustion into a mechanicalenergy (e.g., rotation of an output shaft). For instance, while thecombustion chambers of the engine 10 are defined by cylinders andcorresponding pistons, it should be also appreciated that the engine mayhave any number of suitably configured combustion chambers. In someembodiments, the engine may have multiple pistons (e.g., two, three,etc.) driven from and/or operating in a single cylinder, whichcollectively may define a combustion chamber. Moreover, as noted above,in one or more embodiments, the engine may be a non-reciprocating and/orpistonless engine and may convert pressure produced during combustiondirectly into rotating motion (e.g., wave disk engine, Wankel engine,etc.).

As mentioned above, the engine may include an output shaft. For example,the engine 10 includes a crankshaft 13 that may be rotatably positionedin and/or secured to the block 12. Furthermore, as described in moredetail below, in some embodiments, pistons reciprocate in thecorresponding cylinders to produce rotation of the crankshaft 13. Insome examples, the pistons are rotatably connected to the crankshaft 13,and reciprocation thereof produces corresponding rotation of thecrankshaft 13. Generally, the crankshaft 13 may be connected to anynumber of suitable devices or systems and may provide rotational powerthereto.

In an embodiment, reciprocating movement of the pistons in the cylindersis generated from combustion of fuel and an oxidant (e.g., air) in thecylinder. For instance, the cylinders are at least partially sealedduring the combustion and the pressure produced from the combustionexerts force onto the corresponding pistons, thereby producing linearand reciprocating movement thereof (as described above). For example,the engine 10 includes a cylinder head 14 connected to or integratedwith the block 12, and the cylinder head 14 and block 12, collectively,seal or close the cylinders in a manner that may form substantiallypressure tight environment during combustion of fuel and air in thecylinders.

In some examples, to facilitate sealing between the block 12 and thecylinder head 14, a head gasket may be positioned therebetween. Itshould be appreciated, however, that the engine may have any number ofsuitable configurations and, in some instances, may not require a headgasket. For instance, the block 12 and cylinder head 14 may beintegrally formed.

As described above, air, fuel, fuel-air mixture, or combinations thereofmay be injected directly into one or more of the cylinders. For example,the engine 10 includes fuel lines 24 operably connected with thecorresponding cylinders, such that fuel may be injected through the fuelline and directly into the cylinders. It should be appreciated that one,some, or all of the cylinders may include any suitable number of fuellines operably connected thereto.

In an embodiment, the engine 10 includes a fuel sensor 28 (e.g., octanesensor). In at least one example, the fuel sensor 28 is operablyconnected to the fuel lines 24 to detect the type of fuel therein.Accordingly, for example, the engine may receive any suitable fuel(e.g., any fuel that may be detected and/or identified by the sensor 28For example, the fuel sensor 28 may differentiate among gasoline(petrol), ethanol, diesel, liquefied natural gas (LNG), liquefiedpetroleum gas (LPG), hydrogen, etc. It should be appreciated that theone, some, or all of the fuel lines 24 may include a separate fuelsensor 28. In an embodiment, the fuel sensor 28 may be configured todetect the amount of ethanol in gasoline and/or in a similar type offuel.

In some embodiments, as described below in more detail, the engine 10includes a control mechanism for regulating the flow or injection offuel from the fuel lines 24 into the corresponding cylinders. Forexample, the engine may include valves, fuel injectors, etc., which maybe positioned between the fuel line 24 and the cylinder (e.g., the fuellines 24 may connect to corresponding fuel injectors that may regulatesupply and/or injection of fuel into such cylinders).

In some embodiments, the engine 10 includes air lines 26 operablyconnected to the corresponding cylinders. It should be appreciated thatone, some, or all of cylinders may include one or more air linesoperably connected thereto. The air lines 26 may supply one or moreoxidants into the cylinders of the engine 10. As described below, theengine may include one or more mechanisms for controlling the flow orsupply of the oxidants from the air lines 26 into the cylinders (e.g.,valves, air injectors, etc.). Generally, any number of suitableoxidants, such as air, may be injected directly into the cylinder(s).For example, similar to the fuel injectors, a valve or an air injectormay be positioned between the air lines 26 and the cylinder and mayregulate supply or injection of air into the cylinder (e.g., air lines26 may be operably connected to corresponding air injectors, which mayregulate air flow from the air lines 26 into the cylinder(s)).

In an embodiment, the air lines 26 connect to an air intake manifold 16and may receive air therefrom. It should be appreciated that one, some,or all of the air lines may be connected to the air intake manifold 16and may receive air therefrom. Alternatively, one or more of the airlines may be connected to any number of suitable sources of oxidant(e.g., directly connected to a compressor, to a reservoir tank oraccumulator, etc.). In any event, the air lines 26 may supply air intothe cylinders of the engine 10.

As described below in more detail, the intake manifold 16 may distributeair to the various air lines 26 connected thereto (e.g., the air in theintake manifold 16 may be compressed). In other words, in at least oneembodiment, the air lines 26 may be connected to a source of compressedair. It should be appreciated, however, that a particular source ofcompressed air to the air lines 26 may vary from one embodiment to thenext (e.g., the source of compressed air may include a compressed airtank).

Generally, the intake manifold 16 forms an enclosure that is configuredto contain and distribute air to the air lines 26. In some embodiments,the intake manifold 16 has a generally tubular, cylindrical shape withclosed ends. It should be appreciated, however, that the intake manifoldmay have any number of suitable shapes and/or sizes (e.g., rectangularcross-sectional shape, etc.). In any event, air may be supplied into theintake manifold 16 and may be further distributed thereby to the airlines 26 connected thereto.

In some embodiments, a compressor 18 is operably connected to the intakemanifold 16 to supply air (e.g., compressed air) thereto, which may befurther distributed through the air lines 26 into the cylinders.Generally, the compressor 18 may be any suitable compressor that mayoperate independent of operation of the engine 10 (e.g., the compressor18 may be electrically powered. Additionally or alternatively, thecompressor 18 may be at least in part driven or operated by or from therotation of the crankshaft 13. In any event, compressor 18 may compressair and may supply the compressed air to the intake manifold 16.

In some embodiments, the engine may include one or more cylindersconfigured and/or dedicated for compressing air that may be supplied tothe air lines 26, intake manifold 16, air injectors (described below inmore detail), or combinations of the foregoing. For example, the enginemay include one or more cylinders in fluid communication with outsideenvironment and in fluid communication with the air lines 26, intakemanifold 16, air injectors (described below in more detail), orcombinations of the foregoing. Corresponding one or more pistons maymove or reciprocate in the cylinders to intake and compress the airtherein. For example, the internal space of the cylinder may besubstantially sealed until a suitable pressure is reached and,subsequently, one or more valves may open to allow the compressed air toflow into and/or toward the air lines 26, intake manifold 16, airinjectors (described below in more detail), or combinations of theforegoing. In an embodiment, the pistons may be connected to thecrankshaft in a similar manner as the power pistons of the engine (e.g.,pistons that rotate the crankshaft, as described below). In other words,in some embodiments, a compressor may be integrated with the engine.

In one or more examples, the engine may include one or more filters,which may improve quality of the air supplied into the cylinders. Forinstance, a HEPA filter, a water separation filter, etc., may be placedbetween the compressor 18 and the cylinders of the engine (e.g., betweenthe compressor 18 and the intake manifold 16). Such filter(s) may removeparticles and/or liquids from the air entering the manifold 16 and/orcylinders of the engine.

The engine according to at least one embodiment may include atemperature sensor that may determine or measure the temperature of airbefore injection thereof into the cylinder. For example, the engine 10includes a temperature sensor 17 that may sense temperature of the airin the intake manifold 16. In the illustrated embodiment, the engine 10includes a pressure sensor 19 (e.g., a manifold absolute pressure sensor(MAP)). For example, a controller 5 may operate the air injectors(described below) in a manner that injects a selected (e.g., calculated)and/or predetermined amount of air into the cylinder at least in partbased on the readings from the pressure sensor 19 and/or temperaturesensor 17. It should be appreciated, however, that one or more sensorfunctions may be included within a single sensor and/or one or moresensors may be included within a single enclosure. Moreover, in someembodiments, the engine may include one or more different sensors or nosensors (e.g., such as to be manually and/or electromechanicallyoperated).

Generally, as mentioned above, after combustion of fuel in the engine'scombustion chamber, the produced gas is expelled from the combustionchamber (e.g., to allow additional fuel and air to enter the chamber).For example, piston movement in the cylinder may expel the exhaust gasfrom the cylinder through one or more connections and into the exhaustmanifold 20. Hence, for example, the engine 10 includes exhaustconnections. More specifically, in an embodiment, the engine 10 includesan exhaust manifold 20 operably connected to the cylinders, such thatthe exhaust gas from the cylinders may enter the exhaust manifold 20.

As described below in more detail, the engine according to one or moreembodiments may include one or more exhaust valves that may control theflow of exhaust gas from the cylinders into the exhaust manifold.Moreover, generally, the exhaust manifold may be similar to the intakemanifold. For example, the exhaust manifold 20 has a tubular shape andcapped ends, which may be similar to a gas cylinder. It should beappreciated, however, that the exhaust manifold may have any suitableshape and/or size.

FIGS. 2-3 illustrate respective side view and back isometric view of theengine 10 according to an embodiment. In the illustrated embodiment,exhaust lines 50 connect the exhaust manifold 20 to the cylinders of theengine 10. It should be appreciated, however, that in some examples, theexhaust gas may exit one, some, or all of the cylinders in any number ofsuitable ways (e.g., without entering the exhaust lines and/or exhaustmanifold). In one or more embodiments, the engine may have any number ofsuitable exhaust systems in addition to and/or in lieu of the exhaustdescribed herein.

In the illustrated embodiment, the engine 10 includes exhaust valves 52operably connected to the corresponding exhaust lines 50 to controloutflow of exhaust gas from the cylinders. For example, the exhaustvalves 52 may be positioned on the corresponding exhaust lines 52 andmay allow and restrict gas flow therethrough. Additionally oralternatively, one, some, or all of the exhaust valves may be positionedbetween the exhaust lines 50 and the cylinders (e.g., exhaust valves maybe positioned inside the cylinder(s), just outside the cylinder(s), orotherwise between the exhaust lines 50 and the cylinders and/or thecylinder head 14).

Generally, to control the outflow of the exhaust gasses, the exhaustvalves 52 may be operated between fully open position (e.g., leastrestrictive or unrestricted outflow through the exhaust lines 50) andfully closed position (e.g., substantially or completely restrictedoutflow through the exhaust lines 50). Moreover, the exhaust valves 52may be operated to restrict outflow from the cylinders at any number ofpartially restricted positions between the fully open and fully closedpositions. In any event, exhaust gas flow from one, some, or each of thecylinders into the exhaust manifold 20 may be controlled by acorresponding exhaust valve 52 that may be electrically orelectromechanically actuated, hydraulically actuated, pneumaticallyactuated, etc., to allow exhaust gas to flow out of the cylinders (e.g.,into the exhaust manifold 20). In an example, the exhaust valves 52 maybe actuated from the controller 5. Hence, the timing of the openingand/or closing of the exhaust valves 52 may be electronically controlledand may be based on any number of suitable parameters or inputs.

When the exhaust valves 52 are closed, the corresponding cylinders maybe substantially sealed, such that combustion of the fuel may producepressure therein and may exert force onto and move the pistons, therebyrotating the crankshaft and generating mechanical output of the engine10. The exhaust valves 52 may be selectively opened to allow the exhaustgas to exit the cylinder during and/or after combustion. Moreover, insome embodiments, negative pressure or partial vacuum may be created inthe exhaust manifold 50 to assist with removal of the exhaust gas fromthe cylinder(s). In any event, the exhaust valves 52 may be operated toproduce a sealed environment in one, some, or all of the correspondingcylinder during combustion and to allow exhaust gas to exit the cylinderduring and/or after combustion (e.g., the controller 5 may operate theexhaust valves 52).

The engine according to one or more embodiments may include one or moresensors (e.g., oxygen sensors) to detect presence and/or amount ofoxygen in the exhaust gas. For instance, the engine 10 includes anexhaust or oxygen sensor 54 attached to the exhaust lines 50, such thatthe sensor 54 may detect and/or measure the amount of oxygen in theexhaust gas passing through the exhaust lines 50 into the exhaustmanifold 20. It should be appreciated that, generally, the engine mayinclude any number of suitable sensors, which may detect and/or measurecomposition of the exhaust gas (e.g., as the exhaust gas passes from thecylinder into the exhaust manifold), temperature of the exhaust gas,etc. In an example, the engine 10 may include one or more so-called“five gas sensors,” which may detect and/or measure the composition ofthe exhaust gas (e.g., sensors configured to detect or identify carbondioxide (CO2), carbon monoxide (CO), oxides of nitrogen (NOx), etc.).

In the illustrated embodiment, fuel lines 24 connect to a distributionrail 22. For example, the distribution rail 22 is operably or fluidlyconnected to a fuel supply reservoir (e.g., fuel tank). As such, fuelmay be distributed (e.g., pumped) from the fuel supply reservoir to thedistribution rail 22 and subsequently into the fuel lines 24. Asdescribed above, from the fuel lines 24, the fuel may be injecteddirectly into the cylinders of the engine 10 (e.g., the fuel in the fuellines 24 may be pressurized and a fuel injector 30 may control injectionof the fuel into the cylinders).

As described above, in the illustrated embodiment, the engine 10includes air lines 26, which may be sized and configured to inject asuitable amount of air into the cylinders of the engine 10. Moreover,air lines may be connected to the intake manifold (e.g., air lines 26 ofthe engine 10 are connected to the intake manifold 16). In anembodiment, the intake manifold 16 may be positioned opposite to theexhaust manifold 20. It should be appreciated that the intake manifoldand the exhaust manifold may be positioned at any location and/ororientation relative to the engine as well as relative to each other.

Generally, the engine according to one or more embodiments may includeone or more sensors for identifying or sensing incorrect combustionand/or detonation of the fuel in one, some, or all of the cylinders. Inthe illustrated embodiment, as shown in FIGS. 2 and 3, the engine 10includes knock sensors 56 associated with the cylinders thereof todetect detonation of the fuel in the corresponding cylinders. Forexample, the controller 5 may adjust amount of injected fuel, timing offuel injection, amount of injected air, timing of air injection, timingof spark in the cylinder, or combinations thereof at least in part basedon a signal received from the knock sensors 56. Moreover, it should beappreciated that one, some, or all of the sensors described herein maybe coupled to and/or operated by the controller 5. Moreover, asdescribed below in more detail, the controller 5 may control fuelpressure, fuel injectors, air pressure, exhaust pressure, air injectors,spark plugs, etc., at least in part based on the signal or informationreceived from the sensors.

FIG. 4 is a partial longitudinal cross-sectional view of the engine 10(i.e., cross-section passing through multiple cylinders along the lengthof the engine 10), and FIG. 5 is a transverse cross-sectional view ofthe engine 10 (i.e., passing through a single cylinder and along thewidth of the engine 10) according to an embodiment. As shown in FIGS.4-5 and described above, the engine 10 includes cylinders 15 andcorresponding pistons 21 that may reciprocate in the cylinders 15,thereby rotating the crankshaft and generating mechanical power outputof the engine 10.

As mentioned above, the combustion chambers of a reciprocating enginemay be formed by the cylinders and corresponding pistons. For example,the engine 10 includes combustion chambers 23 formed or defined by thecylinders 15 and corresponding pistons 21. It should be appreciated thatthe actual volume of the combustion chamber may change depending on theposition of the piston therein during ignition and/or combustion of fuel(e.g., as the piston reciprocated between bottom dead center and topdead center positions in the cylinder). Moreover, as discussed below inmore detail, combustion volume within the combustion chamber may dependon the amount of air injected in the cylinder. In other words, thecombustion volume may be the volume of the gas (e.g., air) in thecombustion chamber when the gas is at atmospheric pressure.

Generally, fuel may be directly injected into the cylinders 15. Forexample, the fuel may be injected directly into the cylinders throughcorresponding fuel ports, which may open into the correspondingcylinders of the engine. In the illustrated embodiment, the engine 10includes fuel ports 36 that open directly into the cylinders (e.g., fromthe cylinder head 14). More specifically, the fuel lines 24 connect tocorresponding fuel injectors 30 located and/or secured in the fuelinjection ports 38. In an embodiment, the fuel injectors 30 may beoperated to allow or restrict fuel flow or injection from the fuel lines24 into the corresponding cylinders 15. It should be also appreciatedthat, the engine may include any number of suitable mechanisms forinjecting fuel into the cylinders.

In addition to or in lieu of directly injecting fuel into the cylinder,in some instance, air may be injected directly into the cylinders of theengine. In the illustrated embodiment, the engine 10 includes airinjection ports 40 that open into the corresponding cylinders 15 (e.g.,from the cylinder head 14). For example, the air lines 26 are connectedto one or more corresponding air injectors 34, which may inject airdirectly into the corresponding cylinders 15 through the air injectionports 40. In some instances, the air injectors 34 are positioned and/orsecured in the corresponding air injection ports 40 and may beconfigured to inject air thereto from air lines 26. As mentioned above,the controller may control operation of the air injectors 34 (e.g.,timing of the injection, duration and/or amount of the injection, etc.).

Generally, air and/or fuel may injected into the cylinder at any numberof suitable angles and/or locations. For example, at least some of theair may be injected such as to form a swirl effect that may facilitatemixing the air with the fuel inside the cylinder. In an embodiment, theair and/or fuel may be injected from a location or ports in the cylinderhead (e.g., air may be injected along a generally parallel directionrelative to the movement of the piston 21, which may include one or morepockets or recesses that may direct the air in a manner that produces aswirl effect inside the cylinder). Alternatively or additionally, atleast some of the air and/or fuel may be injected along a generallyperpendicular direction relative to the movement of the piston 21. Forexample, air may be injected at a location substantially opposing thelocation of the fuel injection. Furthermore, it should be appreciatedthat the air injectors 34 and/or the fuel injectors 30 maycorrespondingly inject air and fuel at multiple angles and/or at a sprayangle or fan, such as to facilitate mixing of the air and fuel insidethe cylinder.

The air injectors 34 may include any suitable valve and/or gagingmechanism that may regulate and/or control air injection into thecorresponding cylinders. In some embodiments, the air injectors 34 maybe similar to or the same as fuel injectors (e.g., GDI injectors). Forexample, the fuel injectors may be similar to or the same ascommercially available GDI or FSI fuel injectors, such as FSI fuelinjectors (e.g., manufactured by Bosch), Diesel Direct Injectors, etc.,which may be electrically or electronically controlled (e.g., by thecontroller 5) and may be operably connected to the fuel supply (e.g.,via a distribution elements, such as the distribution rail 22).

In any event, the air injectors 34 may be configured to be controlled toallow a predetermined and/or controlled amount of air from the air lines26 into the corresponding cylinders 15 of the engine 10. Moreover,injection of air into the cylinders may be generally unobstructed. Forexample, as noted above, the injection ports 40 open directly into thecylinders, without any obstruction that may interfere with or impede airflow into the cylinders 15. Alternatively, in some embodiments, theengine may include one or more obstructions or redirection mechanisms(e.g., baffles) that may guide and/or distribute the air in thecylinders 15

In some embodiments, the controller may regulate or control the amountof air (e.g., a volume of air at a selected pressure or mass of air)injected into the corresponding cylinders 15 and produce a predeterminecombustion volume. Hence, under some operating conditions, thecontroller may operate the air injector 34 to inject an amount of airthat may have the same volume as the volume of the cylinder (e.g., thevolume of the cylinder when the piston 21 is at bottom dead center). Insome instances, the controller 5 may operate the air injectors 34 toinject the amount of air that may have a greater volume (e.g., atatmospheric pressure) than the volume of the cylinder 15 (e.g., therebyincreasing the operating volume of the cylinder 15).

Moreover, in some examples, the controller 5 may operate the airinjectors 34 to inject the amount of air that may be less than thevolume of the cylinder 15 (e.g., thereby decreasing the operating volumeof the cylinder 15 and/or producing below atmospheric pressure in thecylinder 15). It should be also appreciated that reducing the pressurein the cylinder 15 to below atmospheric (e.g., operating the cylinder 15at partial vacuum at some portions of the operating cycle) may improveor aid in vaporizing the fuel that may be injected into the cylinder 15,thereby improving combustion.

In some embodiments, as shown in FIGS. 4-5, the fuel and/or airinjection ports 38, 40 and/or corresponding fuel and air injectors 30,34 are oriented approximately parallel to the movement of the pistons21. Additionally or alternatively, the fuel and/or air injection portsand/or corresponding fuel and air injectors may have non-parallelorientation relative to the movement of the pistons 21. Furthermore, insome examples, the fuel and/or air injection ports and/or correspondingfuel and air injectors may be located in one or more sidewalls of thecylinder.

In one or more embodiments, one, some, or each of the cylinders of theengine may have multiple fuel and/or air injection ports. In any event,the fuel and/or air injection ports may have any suitable orientationrelative to a center axis of the cylinder or to movement of the pistonin the cylinder. As such, fuel and/or air may be injected into thecylinder in a manner that may produce a suitable distribution thereof inthe cylinder (e.g., optimize distribution). In some examples, the fueland/or air injectors may be operated sequentially or asynchronously toproduce a suitable distribution and/or mixing of the fuel and air in thecylinder.

As mentioned above, the air and/or fuel may be injected into thecylinders, generally, unobstructed (e.g., through corresponding fuel andair injection ports 38, 40, which may be substantially unobstructed byvalves or other elements or components of the engine 10). Hence, theamount of air and/or fuel injected into the cylinder may be precisely orbetter controlled (e.g., as compared with conventional engines includingvalves). Additionally or alternatively, injection velocities of the fueland/or air may be controlled to produce suitable mixing thereof in thecylinder. For instance, fuel and/or air may be injected into thecylinder(s) in any number of suitable sequences or stages ofinjection(s) and/or at any number of suitable angles (relative to thecylinder and/or to one another).

Moreover, while, in some embodiments, the fuel and air may be injectedinto the cylinders through separate or individual injection port and maymix in the cylinder, this disclosure is not so limited. For example, theair and fuel may enter one, some, or all of the cylinders from the sameport (e.g., each cylinder may include a single port for injecting bothair and fuel therethrough). In an embodiment, the air and fuel may be atleast partially premixed before entering the cylinder (e.g., the air andfuel may be at least partially premixed near the injection port).

In an embodiment, the engine 10 includes one or more spark plugs 46 toignite the fuel-air mixture in the corresponding cylinders 15. Forexample, threaded openings may open into the cylinder 15 (e.g., from thecylinder head 14) and may secure corresponding spark plugs 46 relativeto the cylinder 15. In any event, in some instances, the spark plugs 46may be operated to ignite the fuel-air mixture in the correspondingcylinders 15 (e.g., a controller may control and/or supply power to thespark plugs based on a selected, predetermined, and/or adjustabletiming).

In one or more embodiments, one, some, or all of the cylinders 15 of theengine 10 may operate without the spark plug 46 and/or without operatingone, some, or all of the spark plugs 46. For example, diesel may beinjected into one, some, or all of the cylinders 15 of the engine andmay be ignited and combusted without spark ignition. Moreover, in anembodiment, one or some of the cylinders 15 may receive gasoline, whichmay be ignited by a spark from the corresponding spark plugs 46, whileone or some of the cylinders 15 may receive diesel, which may becombusted during compression thereof (e.g., without operating thecorresponding spark plugs 46).

In some examples, the spark plugs 46 may be at least partially recessedin the cylinder head 14. For instance, the cylinder head 14 may includerecesses 42, which may be connected to or extend from correspondingthreaded openings. As mentioned above, the spark plugs 46 may be screwedinto the threaded openings, such that spark generating portions of thespark plugs extend into the corresponding cylinders 15.

As described above, exhaust gas from the cylinders 15 may exit into theexhaust manifold 20. In the illustrated embodiment, the engine 10includes exhaust ports 48 in fluid communication with one, some, or eachcylinder 15. In some examples, the exhaust ports 48 are in fluidcommunication with the corresponding exhaust lines 50, which may beconnected to the manifold 20. Hence, the exhaust gas produced duringcombustion of fuel may exit the cylinders 15 through the exhaust ports48, into the exhaust lines 50, and further into the exhaust manifold 20.In any event, the exhaust gas may exit the cylinders 15 throughcorresponding exhaust ports 48.

In some instances, the engine 10 may include exhaust valves 52, whichmay selectively open and/or close flow at and/or through the exhaustports 48 (e.g., one, some, or all of the exhaust valves 52 may beelectrically or electronically controlled by the controller). Morespecifically, in some embodiments, closing the exhaust valves 52provides at least partially sealed or hermetic environment in thecorresponding cylinders 15 (e.g., during combustion of the fuel).Conversely, for example, opening the exhaust valves 52 allows theexhaust gas in the corresponding cylinders 15 to exit and/or to bewithdrawn therefrom.

The operation of the engine and/or components or elements thereof alsomay be represented schematically. For example, the engine may include ormay be connected to a fuel system 90 a, which is representedschematically with a block diagram shown in FIG. 6. As mentioned above,the engine may include any number of cylinders, which may vary from oneembodiment to the next. For easy of description, the block diagram ofFIG. 6 illustrates the fuel system 90 a that is included or connected toa four cylinder engine.

In an embodiment, fuel in the fuel system 90 a is pumped from a fueltank 58 a by a pump 60 a. It should be appreciated that, in someembodiments, the fuel may be advanced from the fuel tank with any numberof suitable devices or configurations (e.g., the fuel may be gravity fedfrom the fuel tank). Additionally or alternatively, in the illustratedembodiment, the fuel system 90 a includes a pressure sensor 62 a (e.g.,in fluid communication with the fuel) to measure the pressure of thefuel in the fuel lines (e.g., directly after the fuel exits the fuelpump 60 a).

In an embodiment, the fuel pump 60 a is in fluid communication with andmay pump the fuel into the distribution rail 22 a. As described above,the distribution rail 22 a is connected to the fuel into fuel lines 24 aand may distribute fuel thereto. The fuel lines 24 a may distribute thefuel toward and/or into corresponding cylinders engine. In anembodiment, the fuel system 90 a includes a fuel pressure regulator 64a, which may regulate the pressure in the fuel lines 24 a and/or in thedistribution rail 22 a. For example, the fuel pressure regulator 64 amay facilitate maintaining an approximately constant pressure in thefuel rail 22 a and/or in the fuel lines 24 a.

In some instances, the fuel pressure regulator 64 a may release orreduce fuel pressure in the lines and/or distribution rail 22 a toproduce a suitable and/or selected and/or predetermined pressuretherein. For example, the fuel pressure regulator 64 a may reducepressure in the distribution rail 22 a by allowing some fuel to exit thedistribution rail 22 a. In some embodiments, the fuel exiting thedistribution rail 22 a may flow or may be pumped back to the fuel tank58 a (e.g., along a return line 66 a).

In at least one embodiment, the fuel system 90 a includes one or morefuel sensors 28 a that correspond to the fuel lines 24 a leading to thecylinders of the engine. For instance, the fuel sensors 28 a may detectthe fuel type in the fuel lines 24 a. Also, as described above, the fuelmay be injected into the cylinders by or through fuel injectors 30 a.For example, the controller may determine the duration of time the fuelinjectors 30 a remain open, such that a selected and/or predeterminedamount of fuel enters the respective cylinders of the engine. It shouldbe appreciated that the controller also may actuate any of the fuelinjectors 30 a at any time and for any duration of time (e.g., toproduce customized injection of fuel for each cylinder). Moreover, thecontroller may operate the fuel injectors 30 a at least in part based onthe signal or reading from one, some, or all of the fuel sensors 28 a.

While in some embodiments the fuel pressure regulator may be locatedsequentially after the distribution rail 22 (e.g., downstream of thefuel flow), this disclosure is not so limited. FIG. 7 a schematic blockdiagram of a fuel system 90 b according to one or more embodiments. Asshown in FIG. 7, in at least one example, a fuel pressure regulator 64 bis located between the distribution rail 22 b and a compressed gas tank58 b (e.g., compressed gaseous fuel may be located in the compressed gastank 58 b). In an embodiment, the fuel in the compressed gas tank 58 bmay be pressurized by a fuel pump (if in liquid phase) or by acompressor (if in gas phase) and may be maintained at an approximatelyconstant and/or selected and/or predetermined pressure in the compressedgas tank 58 b. Furthermore, in some embodiments, the fuel system 90 bmay include one or more mechanisms for maintaining the fuel (e.g., inthe distribution rail, in the fuel lines, etc.) at an approximatelyconstant pressure.

The fuel pressure regulator 64 b may be operated by the controller toproduce or generate fuel flow from the compressed gas tank 58 b into thedistribution rail 22 b (e.g., as regulated by the controller at least inpart based on the signals or information from the pressure sensor 62 b).For instance, the fuel pressure regulator 64 b may be operated in amanner that the fuel in the distribution rail 22 b and/or in the fuellines 24 b is at an approximately constant pressure. Fuel sensors 28 bcan be operably connected to the fuel lines 24 b between thedistribution rail 22 b and the fuel injectors 30 b.

As described above, the engine may include or may be connected to an airinjection system. FIG. 8 illustrates a schematic block diagram of an airinjection system 95 according to an embodiment. In the illustratedembodiment, the air injection system 95 includes compressor 18 c, whichmay draw air (e.g., at atmospheric pressure) and output pressurized air(e.g., at a pressure that is greater than the atmospheric pressure). Insome embodiments, the air injection system 95 includes a first airpressure sensor 68 that may detect output air pressure of the aircompressor 18 c. Hence, the controller may regulate operation of thecompressor 18 c based at least in part on the readings or signals fromthe air pressure sensor.

In some examples, the air injection system 95 includes an air pressureregulator 70 that may regulate the pressure between the air compressor18 c and the intake manifold 16 c. For example, the air pressureregulator 70 may be set to a selected and/or predetermined pressure ormay be dynamically and/or automatically adjusted (e.g., by thecontroller) during operation of engine 10 c. In at least one embodiment,the air injection system 95 includes a second air pressure sensor 72,which may verify the air pressure in the intake manifold 16 c. Forinstance, the controller may adjust the air pressure regulator 70 atleast in part based on the readings or information from the second airpressure sensor 72, such as to produce a selected, predetermined, and/orsuitable pressure in the intake manifold 16 c and in air lines 26 c thatsupply air to the corresponding cylinders of the engine 10. In anembodiment, the air in the intake manifold 16 c and/or in the air lines26 c may be maintained at an approximately constant pressure.

In one or more embodiments, air injection into the cylinders of theengine may be controlled and/or regulated by air injectors 34 c. Asdescribed above, the air injectors 34 c may control the amount of airthat is injected from the air lines 26 c into corresponding cylinders atany one or more times during the engine's cycle. For example, thecontroller may actuate one, some, or all of the air injectors 34 c atany suitable time and for any suitable duration of time to allow asuitable or selected and/or predetermined amount of air from the airlines 26 c to flow through the corresponding air injectors 34 c andinject into the cylinders of the engine 10 c.

In some embodiments, the engine may idle for a period of time usingcompressed air to power it. In other words, the compressed air may beinjected into the cylinders by sequentially operating the air injectors34 c in a manner that forces pistons downward in a sequence thatproduces rotation of the crankshaft. In an example, the compressed airmay be used to start or assist in starting the engine (e.g., in theevent a starter is disabled or battery power is not available to thestarter). For instance, compressed air may be supplied from a tank(e.g., a reserve tank) that may contain pressurized air. Moreover, insome examples, during operation of the engine, air may be continuouslyadded to and/or circulated from the tank (e.g., from the operation ofthe engine, which may produce compressed air and/or from the aircompressor).

As mentioned above, the engine 10 c may include or may be connected toan exhaust system. For example, the exhaust from the cylinders may enterthe corresponding exhaust line 50 c and may flow into the exhaustmanifold 20 c. In some embodiments, the exhaust manifold 20 c may beconnected to one or more additional components or elements of theexhaust system (e.g., catalytic converter, muffler, etc.). In someembodiments, exhaust valves 52 c can be positioned between the engineand exhaust lines 50 c.

In an embodiment, one, some, or all of the air injectors, fuelinjectors, exhaust valves, or combinations thereof may be mechanicallydecoupled or disconnected from an output shaft (e.g., from thecrankshaft) and/or may be operated (including directly or indirectly,such as by providing instructions for operating) by a controller.Generally, the controller may be any suitable general purpose or specialpurpose computing device, which may be programmable. For example, thecontroller may include one or more processors, memory (e.g., storagememory, RAM, etc.) operably coupled to the processor(s), and aninput/output (I/O) interface for receiving and sending commands orsignals. In any event, the controller may be configured to operation ofone or more elements or components of the engine (e.g., at least in partbased on the information or signals from the sensors described herein).

In an embodiment, the controller may regulate the operation of fuelinjectors, air injectors, exhaust valves, or combinations thereof basedon any number of suitable parameters and/or inputs. In an embodiment,the engine or combustion system may include and/or may be connected to athrottle position sensor, which may detect a change in position of athrottle indicator (e.g., a gas pedal). Moreover, a crankshaft positionsensor may detect position of the crankshaft and may provide informationabout crankshaft position to the controller (e.g., based on thecrankshaft position, the controller may determine the respectivepositions of the pistons in one, some, or all of the cylinders of theengine). In any case, based on any number of suitable parameters and/orinputs, the controller may adjust operation of the engine or any portionthereof (e.g., supply of fuel and/or air to one or some of the cylindersmay be different from one or some of the other cylinders and/or any oneor some of the cylinders may be disabled at any time).

It should be appreciated that, according to one or more embodiments,actuation of the fuel and air injectors and the time for which theyremain actuated or open may be controlled in a manner that provides fueland/or air in stages to each cylinder. For instance, a first charge offuel and/or air may be provided at a first position of the piston, afterthe piston has completed its upward stroke (e.g., top dead center) andas the piston moves down during the down stroke; as the piston movesfurther down, during the down stroke, one or more additional charges offuel and/or air may be provided into the cylinder at one or moreadditional positions of the piston, before the piston reaches the end ofdownward stroke (e.g., bottom dead center). Furthermore, additional oralternative charges of fuel and/or air may be supplied into the cylinderprior to the piston reaching the top or bottom dead center (e.g.,various configuration and staging settings may configure the engine tobe adjustable to the burning characteristics of different fuels).

In some examples, the engine may be operated to produce a rapid increasein power of short duration (e.g., by operating the engine on atwo-stroke cycle). For example, the fuel and air may be injected eachtime a piston commences a downward stroke (instead of every alternatestroke of the four-stroke cycle). Moreover, any one or more cylindersmay be operated on two-stroke cycle to generate a rapid increase inpower output from the engine.

As described above, generally, the internal combustion engine includesat least one combustion chamber and an output shaft rotatable inresponse to combustion of fuel in the combustion chamber(s). Forexample, the internal combustion engine may include an energy conversionmechanism for converting the energy produced during combustion of a fuelin the combustion chamber(s) into mechanical output at the output shaft(e.g., converting pressure increase in the combustion chamber intorotation of the output shaft). In an embodiment, the fuel and oxidizerare injected into the combustion chamber and a combustion reactionproduces a pressure increase therein; the energy conversion mechanismsconfigured to convert the increased pressure in the combustion chamberinto mechanical energy, such as rotation of the output shaft (e.g.,pistons movable in cylinders and connected to the output shaft; ahousing and rotatable rotor connected to the output shaft, etc.).

In any event, in one or more embodiments, a controller or control systemmay control operation of the internal combustion engine by controllinginjection of the fuel and/or air into the combustion chamber and/or bycontrolling exhaust from the combustion chamber. For example, thecontroller may control the engine that may include one or more fuelinjectors and/or one or more air injectors, which may respectivelyinject fuel and oxidant into the combustion chambers (e.g., cylinders)of the engine and exhaust valves that may prevent or allow exhaust toexit corresponding combustion chambers. As described below in moredetail, in at least one embodiment, the fuel injectors, air injectors,exhaust valves, or combinations thereof are mechanically decoupled ordisconnected from the output shaft and may be operated by thecontroller. Also, generally, controlling the amount of injected fueland/or air into the cylinders as well as timing of such injections mayproduce any number of suitable operating conditions for the engine.

In some embodiments, the controller may be operably coupled to one ormore elements or components of the engine and/or may control or actuateoperation thereof. For instance, a control system that includes thecontroller may include any number of suitable sensors that may providevarious inputs to the controller. In some examples, the control systemincludes one or more input interface devices (e.g., a device including auser interface) coupled to the controller, such that the controller mayreceive input therefrom (e.g., input that may be provided by a userand/or may be related to an operating parameter of the engine). Hence,the controller may receive one or more inputs and may operate (directlyor indirectly) elements or components of the engine (and/or elements orcomponents connected to the engine) and, thereby, modify operation ofthe engine. For example, the controller may modify or adjust operationof the engine to change and/or optimize power output, number ofrevolutions per minute (RPM) of the output shaft, direction of rotationof the output shaft, combustion efficiency, combustion volume,combination of the foregoing, etc.

In one or more embodiments, the control system may determine orcalculate an amount of fuel and/or air to be injected into the cylindersof the engine based on one or more operation inputs (e.g., inputs fromthe user of the engine). For example, operation inputs may includeinputs related to a power output requirement, RPM of the output shaft,combustion volume, etc., and the control system may determine parametersfor the engine's elements and/or components to achieve or produce theoperation of the engine that corresponds with the operation input(s).For instance, as described below in more detail, the controller maydetermine the amount of fuel and/or air to inject into the cylindersand/or timing of such injection(s), timing of ignition of the air-fuelmixture in the cylinders, timing and duration of openings of exhaustvalves, etc.

Generally, the internal combustion engine may combust any suitable typeof fuel, such as gasoline (petrol), ethanol, diesel, liquefied naturalgas (LNG), liquefied petroleum gas (LPG), hydrogen, etc. Moreover, anysuitable oxidizer, such as oxygen, may facilitate and/or promotecombustion of the fuel.

As discussed above, the combustion engine 10 (e.g., as shown in FIG. 1)may be computer controlled and may be operably coupled to the controller5, according to an embodiment. Again, it should be appreciated that theengine may have any number of cylinders and any number of suitablecylinder arrangements, as discussed above (e.g., V, rotary, boxer,etc.).

As described above, the fuel and/or air may be injected directly intothe cylinders of the engine 10. For example, the engine 10 includes fuelinjectors 30 and air injectors 26 (FIG. 4) that are associated withcorresponding cylinders of the engine 10. In some embodiments, thecontroller 5 operates (which includes operating directly or indirectly,such as by providing instructions for operating) the fuel injector 30and/or air injectors 26, as described below in more detail.

As described above, the air injectors 26 may be connected to any numberof sources or supplies of air or any number of suitable oxidants. In oneor more embodiments, the air injectors 26 connect to an air intakemanifold 16. For example, the air intake manifold 16 may contain and/ordistribute air (e.g., compressed air) to the air injectors 26 (e.g., viaone or more corresponding air lines between the air injectors 26 and theintake manifold 16. In some embodiments, the air intake manifold 16 maybe in fluid communication with a compressor 18, which may supplycompressed air into the air intake manifold. Analogously the fuelinjectors 30 may be connected to a supply of fuel (e.g., a fuel pump maysupply fuel to or toward the fuel injectors 30).

In one or more embodiments, the controller 5 operates (directly orindirectly, such as by providing instructions for operating) the fuelinjector 30 and/or air injectors 26, as described below in more detail.For example, the exhaust valves 52 of the combustion engine 10 may beoperably coupled to the controller 5 and may be operated thereby betweenopen and closed positions, such that in the open positions exhaust mayexit the cylinder during and/or after combustion, and in the closedposition the exhaust valves 52 at least partially prevent exhaust fromexiting the corresponding cylinders. Furthermore, as mentioned above,the controller 5 may be connected to one or more sensors that mayprovide information about operation of the engine 10 and/or aboutoperating parameters for the operation of the engine 10. In someembodiments, an octane or fuel sensor is connected to the controller 5and positioned in contact with the fuel flowing toward or to the fuelinjector 30 (FIG. 4). Hence, the controller 5 may receive information orsignals related to the fuel flowing toward and/or to the cylinders ofthe engine 10.

The controller 5 may also be connected to one or more sensors that mayprovide information about the oxidant being supplied to the cylinders ofthe engine 10. For example, the engine 10 may include a pressure and/ortemperature sensor 17 connected to the controller 5 and in communicationwith the air in the intake manifold 16. Similarly, the controller 5 maybe connected to one or more sensors that may provide information aboutthe exhaust exiting one or more cylinders of the engine 10.

In an embodiment, the engine 10 includes exhaust sensors 54 incommunication with the exhaust exiting corresponding cylinders of theengine 10 and connected to the controller 5. For example, the exhaustsensors 54 may detect or determine the amount of oxygen present in theexhaust gases exiting the corresponding cylinders of the engine 10.Furthermore, in some examples, the controller 5 may be connected to oneor more oxygen sensors in communication with the incoming air (e.g., airin the intake manifold 16, in air lines connecting the intake manifold16 to the air injectors 26). Hence, the controller may receive input orsignals related to the oxygen content or concentration in the airflowing toward or to injection in the combustion chambers of the engine10.

As described below in more detail, the controller may be connected toand/or receive information from any number of suitable sensors, such asposition sensors connected to the output shaft, knock sensors, throttleposition sensors, etc. Moreover, in some examples, the controller mayreceive input from sensors and/or input devices that may be unassociatedwith the engine. In any event, the controller may operate the airinjectors, fuel injectors, exhaust valves, or combinations thereof atleast in part based on the information or signals received from thesensors connected to the controller.

FIG. 9 illustrates a flow chart of operations or acts that may beperformed by a controller of a control system, which may controlcombustion in and/or operation of the internal combustion engine,according to at least one embodiment. In an embodiment, the controllerperforms or executes an act 100 of receiving one or more operationinputs related to an operating parameter of an engine. For example, thecontroller may receive input or information related to power outputand/or RPM to be produced by the engine (e.g., a request to increase RPMof the engine's crankshaft). Generally, the input may be provided orsupplied to the controller in any number of suitable ways and/or fromany number of suitable input interfaces and/or input interface devices.For example, in a vehicle, the input interface device may be a throttle(e.g., a throttle pedal, lever, handle, etc.).

In some instances, one or more sensors (e.g., position sensors) mayreceive input from the throttle and transmit a translated input (e.g.,displacement of the throttle) to the control system. Hence, for example,displacement of the throttle pedal (e.g., input from a user) may bedigitized or translated into a corresponding input transmitted or sentto the controller that may indicate to the controller the amount ofdisplacement of the throttle pedal produced by the user. In someinstances, displacement of the throttle pedal (as indicated by thesignal or input from the sensor coupled to the throttle pedal) may beprocessed and/or associated by the controller with one or more operatingparameters of the engine, such as RPM, power output, etc.

Also, because displacement(s) of the throttle pedal may be digitized,combinations or patterns of displacements (e.g., multiple shortdisplacements, multiple long displacement, combinations thereof, etc.)may be correlated by the controller with a particular operatingparameter of the engine. For example, two long displacements may becorrelated by the controller with a selected and/or predetermined poweroutput or percentage increase of the power output or RPM of the engine.In any event, the controller may receive one or more inputs related to adesired or requested power output and/or RPM of the engine.

In alternative or additional embodiments, the controller may receive aninput for a requested combustion volume. For instance, a suitable inputinterface may include a dial, keyed interface, touchpad, combination ofthe foregoing, etc. In any case, the input interface may facilitateentry of the desired or requested combustion volume for the engine,which may be sent or transmitted to the controller. In some embodiments,the input related to operating parameter(s) may include a requestedsound (e.g., frequency, tonality, etc.) to be produced by the engine.For example, an interface may provide or display sound options (e.g.,sounds of various engines or engine models) and receive selection(s) ofsuch options; the interface may transmit to the controller suchselections as input related to the operating parameter of the engine.

Moreover, in one or more embodiments, the input(s) may be indirectlyrelated to one or more operating parameters of the engine. For instance,the engine may be included in an engine-driven vehicle. Hence, forexample, the input may be related to a speed of the vehicle, which maydepend on orientation of the vehicle (e.g., inclined, declined, etc.),maneuvers of the vehicle, weather conditions, etc. In such example, theinput from the input interface device (e.g., cruise control) may betranslated or converted to one or more parameters or inputs that may berelated to operating parameter(s) of the engine, such as RPM of thecrankshaft.

In some embodiments, inputs (e.g., inputs that may be indirectly relatedto the operating parameters of the engine) may be related to and/or atleast partially based on anticipated power requirements for the engine.For instance, operation input(s) for controlling an engine of anengine-powered vehicle may relate to and/or may be at least partiallybased on the weight of the vehicle and its cargo, anticipated or plannedroute (e.g., uphill, downhill, turns, etc.), etc. Hence, as describedbelow in more detail, the controller may correlate such input with theoperating parameter(s) of the engine.

In some embodiments, the operation input(s) may include identifying aparticular type of fuel and/or oxidant that will be supplied into theengine's cylinders. For example, inputs may include selections orentries of fuel type and oxidant combinations, which may be received viaany suitable interface that may be coupled to the controller.Additionally or alternatively, the input(s) related to the fuel and/oroxidant types may be received from one or more sensors. In someembodiments, the controller performs or executes an act 110 of receivinginput from one or more sensors. For instance, the controller may receiveinput from fuel and/or oxidant sensors. While from time to time thedescription refers to a “cylinder” or “cylinders,” it should beappreciated that such references are made for simplicity and the enginemay include any suitable combustion chamber(s), as described above.

In at least one embodiment, the controller may receive input from one ormore air pressure sensors, which may indicate pressure in the air linesand/or in air intake manifold that may collectively supply air (or otheroxidant) into the cylinders. In other words, the controller may receiveinformation about the pressure or percent compression of the air thatmay be forced or injected directly into the cylinders (e.g., withoutinterference of valves). In some instances, the controller also mayreceive input from additional or alternative sensors in communicationwith the air lines and/or in communication with air intake manifold;such sensors may identify the type of oxidant in the air lines and/orquantity thereof (e.g., percent or concentration of Oxygen present inthe air). Furthermore, in some examples, the controller may receiveinput from one or more exhaust sensors. For example, the exhaust sensorsmay provide input related to oxygen content in the exhaust gases thatexit the cylinders of the engine.

In an embodiment, the controller may receive input from fuel sensorsthat may identify the type of fuel being supplied to the cylinders. Forexample, the fuel sensors may be in communication with fuel and mayidentify the type thereof (e.g., distinguishing gasoline, diesel,hydrogen, natural gas, propane, etc.). In some instances, one or moresensors also may determine or identify pressure of the fuel (e.g., inthe fuel lines, near the fuel injectors, etc.).

In some embodiments, the controller may receive input or signals relatedto the engine temperature, air temperature, fuel temperature, etc. Forinstance, the controller may receive information related to thetemperature of the engine from one or more sensors (e.g., thermocouples)in thermal communication with one or more portions of the engine. Inadditional or alternative embodiments, the controller may receive inputabout the rotational speed (RPM) and/or position of the engine'scrankshaft. For instance, one or more encoders or similar sensors may beconnected to the crankshaft and may determine the rotational position ofthe crankshaft as well as the rotational speed thereof. Furthermore, anexample, the encoders may be absolute encoders and may maintainpositional information related to the position of the crankshaft. Hence,for example, the encoder may maintain positional information withoutpower supplied thereto and may transmit to the controller input relatedto such information without rotation of the crankshaft (e.g., before theengine runs). It should be appreciated that the encoder may have anysuitable resolution (e.g., 1 degree, ½ degree, ¼ degree, etc.), suchthat the controller receives information or signals related to therotation of the crankshaft at every 1 degree, ½ degree, ¼ degree, etc.Alternatively or additionally, the controller may receive information orsignals related every ¼ turn (e.g., every 90 degrees) of rotation of thecrankshaft.

As described above, in at least one example, the engine may power avehicle. Hence, in some instances, the controller may receive input fromone or more sensors, which may be related to operating conditions ofsuch vehicle. For example, such sensors (e.g., accelerometers,gyroscopes, etc.) may transmit to the controller input that may berelated to movement of the vehicle, such as inclined or uphill movement,decline or downhill movement, turning, pivoting, etc.

In an embodiment, the sensors may include a Global Positioning System(GPS), which may provide global positioning coordinates for the vehiclepowered by the engine. Hence, for instance, as described below in moredetail, the controller may estimate the vehicle's movement at least inpart based on the input received from the GPS. For example, thecontroller may correlate the global position coordinates and/or changethereof with position(s) on a map and may determine location of thevehicle on the map and movement of such vehicle relative to the map.

In one or more embodiments, the controller performs or executes an act120 of determining amount of air to inject into one or more combustionchambers of the engine (e.g., into one or more cylinders of the engine).More specifically, for example, the controller may determine the amountof air to inject into the combustion chamber(s) based on the informationor readings received from the sensors and/or based on the receivedinput(s) related to the operating parameter(s) of the engine. In someinstances, the controller may reference or refer to one or morealgorithms, tables, databases, or combinations thereof to determine theamount of air to inject into the cylinders.

As mentioned above, the controller may correlate one or more inputs withoperating parameter(s) of the engine. In particular, the controller maycorrelate inputs received from one or more users, sensors, etc., withthe operating parameter(s) of the engine. For example, the controllermay process input from a GPS to determine location of the vehicle thatincludes the engine and/or current and anticipate movement thereof(e.g., uphill, downhill, etc.); based on the location and current and/oranticipated movement of the vehicle, the controller may determine one ormore operating parameter(s) of the engine. For instance, the controllermay determine or calculate a combustion volume for the engine based onthe current and/or anticipated movement of the vehicle and/or based oncorrelating current and/or anticipate load and/or power requirements(e.g., the controller may determine an increase in combustion volume tomaintain the current RPM based on anticipate incline in the vehicle'sroute). In some examples, the controller may determine the combustionvolume based on one or more additional or alternative parameters (e.g.,local laws or ordinances related to allowable emissions). For instance,based on local laws or ordinances and based on the input from GPS, thecontroller may determine to reduce combustion volume (e.g., to less thaninternal volume of the cylinder, such that, for example, the combustionvolume is at a pressure below atmospheric pressure).

In some embodiments, the controller refers to a table, chart, one ormore formulas or algorithms, etc., which may correlate selected and/orpredetermined amounts of fuel and air with revolutions per minute (RPM)produced at the crankshaft of the engine. It should be appreciated thatsuch table may vary from one embodiment to the next and from one engineto another. In any event, however, at least in part based on suchtable(s) the controller may determine the amount of air to inject intothe cylinders.

For instance, as mentioned above, the controller may receive inputrelated to a requested operating parameter of the engine, such as RPM ofthe engine's crankshaft. Additionally or alternatively, as noted above,the controller may receive any number of suitable inputs, which may beconverted to and/or correlated with operating parameter(s) of theengine. In an embodiment, based on such input, the controller maydetermine the amount of air to be injected into the cylinders. Forexample, the controller may choose or determine (e.g., based on userpreferences) an optimal amount of air to minimize the amount of fuel forproducing a requested RPM, thereby producing a lean combustion in thecylinder(s), as described below in more detail.

It should be appreciated that, because conventional engines may notprecisely control the amount of air that enters the cylinder, typicalconventional controls may adjust air intake mechanisms (e.g., throttle,turbo, etc.) to achieve a requested RPM. In at least one embodiment,precisely controlling the amount of air that is injected in the cylinder(e.g., by directly injecting a selected and/or predetermined amount ofair into the cylinder) may facilitate producing selected and/orpredetermined RPM based on such injection or series of injections. Inother words, the controller may determine a specific amount of air toinject into the combustion chamber(s), such as cylinders, and produce aselected, predetermined, and/or requested RPM output, as compared with aconventional adjustments to air supply to the cylinders that are madebased on the RPM (e.g., since a conventional controller may not have theinformation about the precise amount of air that enters the cylinder).

Likewise, as mentioned above, the controller may receive one or moreinputs related to a requested volume for one or more cylinders. Forexample, the controller may receive a request to increase (e.g., by100%, 200%, etc.) or decrease (e.g., 20%, 40%, 50%, etc.) the actualcombustion volume of the cylinder. Based on such request, the controllermay determine the amount or volume of air to inject into thecylinder(s). It should be appreciated that, in some instances, thedetermined amount of air to be injected may be less than the actualvolume of the cylinder (e.g., at atmospheric pressure, the volume of airto be injected into the cylinder may be less than the volume of thecylinder).

In some examples, the controller may determine the amount of air toinject into each specific cylinder independently. For example, thecontroller may reduce the amount of air supplied into one or morecylinders, thereby reducing the combustion volume. Alternatively oradditionally, the controller may determine to increase air supply intoone or more cylinders (e.g., based on reduced supply of fuel) to producelean combustion, such as for increased fuel economy. It should beappreciated that, in some instances, lean combustion may have highercombustion temperature, which may lead to increase engine temperature.The controller may determine to selectively produce lean combustion inone or more cylinders and periodically change cylinders that producelean combustion (e.g., based on temperature input from one or moretemperature sensors), in a manner that may avoid overheating the engineand/or damaging elements or components thereof.

In some instances, the controller may adjust the amount of air to beinjected into the cylinders based on the input from one or more exhaustsensors. For instance, the controller may receive input that identifiesthe amount of oxygen in the exhaust gas. As such, the controller mayadjust the previously determine amount of air based on the amount ofoxygen present in the exhaust. Moreover, in some embodiments, thecontroller may adjust the algorithm (e.g., a formula), table values,etc., for making future determinations of the amount of air to beinjected into the cylinder(s) in response to receiving the same orsimilar inputs, such as inputs from one or more of the sensor(s) and/orthe same or similar operation inputs.

In an embodiment, the controller performs or executes an act 130 ofoperating one or more air injectors at least in part based on thedetermined amount of air. In particular, for instance, the controllermay operate (directly or indirectly, such as by providing instructionsfor operating) the air injectors to inject air directly into theengine's cylinders (e.g., injecting air in at least substantiallyunimpeded manner). For example, the controller may open the airinjectors in one, some, or all of the cylinders for a selected and/orpredetermined period or amount of time, which would allow a selected,predetermined, and/or precise amount of air to enter the cylinder. Asmentioned above, the controller may receive inputs that may be relatedto the air pressure at or near the air injectors. As such, for instance,the controller may determine the amount of time required to hold the airinjector(s) open to allow a selected and/or predetermined amount of airto enter the cylinder (e.g., at least in part based on the inputreceived from the air pressure sensor).

In any event, the controller may operate the air injector(s) to providea predetermined and/or precise amount of air into the cylinder(s),thereby operating the engine at one or more selected and/orpredetermined operating parameters (e.g., at selected and/orpredetermined or requested RPM, temperature, fuel efficiency, etc.).Moreover, while the above acts are described in a particular order, itshould be appreciated that such acts may be performed in any number ofsuitable sequences, which may vary from one embodiment to the next. Forexample, the controller may first receive input from one or more sensors(act 110) and subsequently receive one or more operation inputs relatedto operating parameter(s) of an engine (act 100).

As mentioned above, the controller may receive information or signalsfrom any number of suitable sensors or input sources, and suchinformation or signals may be related any number of operating conditionsor parameters of the engine. For instance, the controller may receiveinformation or signals related to the exhaust exiting the combustionchambers of the engine. Furthermore, in some examples, the controllermay operate the air injectors at least in part based on the informationor signals received from the exhaust sensors. For example, FIG. 10illustrates a flow chart of steps or acts that may be performed by acontroller according to at least one embodiment.

More specifically, in an embodiment, the controller performs or executesan act 110 a of receiving a signal related to exhaust gases from one ormore combustion chambers. For example, the controller may receiveinformation or signal from an exhaust sensor, which may indicate or maybe related to the composition of the exhaust gases (e.g., the signal maybe related to the amount of oxygen present in the exhaust).Additionally, in some embodiments, the controller executes or performsan act 120 a of determining an amount of air to inject into one or morecombustion chambers of the engine. In particular, such determination maybe at least in part based on the signals or readings received from theexhaust sensor(s).

For example, based on the amount of residual Oxygen present in theexhaust, the controller may determine the amount of air to inject intothe combustion chamber(s), such that the injected Oxygen is completelyor substantially consumed during the combustion reaction. Hence, atleast one embodiment includes an act 130 a of operating one or more airinjectors at least in part based on the amount of air determined by thecontroller. As noted above, for example, the controller may operate theair injectors by opening and/or maintaining open the air injectors for aselected and/or predetermined amount of time, such that a selectedand/or predetermined amount of air enters the combustion chamber.Additionally or alternatively, the controller may provide informationthat includes the determined amount of air to be injected into thecombustion chambers; the air injectors may be operated based on suchinformation to inject a selected and/or predetermined amount of air intothe combustion chamber(s) of the engine.

Also, in some embodiments, the controller may determine operatingparameters for and/or may operate additional or alternative elements orcomponents that may control operation of the engine. FIG. 11 illustratesa flow chart of steps or acts that may be performed by a controlleraccording to at least one embodiment. Except as otherwise describedherein, the acts described below may be similar to or the same as theacts described above in connection with FIGS. 9-10. In the illustratedexample, the controller performs or executes an act 200 of receiving oneor more operation inputs related to operating parameter(s) of an engineand act 210 of receiving input from one or more sensors, which may besimilar to or the same as acts 100, 110 (FIG. 9).

In an embodiment, the controller performs or executes an act 220 ofdetermining amount of air and/or fuel to inject into one or morecombustion chambers (e.g., cylinders) of the engine, which may be basedat least in part on the operation input(s) and/or on the input(s) fromthe sensor(s). For example, the controller may determine the amount ofair to inject into the cylinder(s) in the same or similar manner asdescribed above. Furthermore, the controller also may determine theamount of fuel to inject into the cylinder(s), thereby determining theair-fuel mixture to be injected into the cylinder(s).

It should be also appreciated that, in some embodiments, the air andfuel may mix outside of the combustion chamber(s) of the engine and maybe injected together. Hence, for example, the controller may providesignals or instructions to one or more controlling elements (e.g.,valves, injectors, etc.) that may dispense selected and/or predeterminedamounts of air and/or fuel, which may mix together outside of thecombustion chamber. Subsequently, the premixed air-fuel mixture may besupplied to (e.g., injected into) the combustion chamber(s) of theengine.

As mentioned above, the controller may receive input from the sensor(s)that may identify the type of fuel (e.g., composition of fuel) in thefuel cell (e.g., gas tank), fuel lines, near fuel injectors, orcombinations thereof. Hence, the controller may determine the amount offuel to be injected into the cylinder(s) at least in part based on thetype of fuel that may be injected into the cylinder(s). In someembodiments, gasoline may be injected into the cylinders (e.g.,oxidation reaction of gasoline may be represented as:25/2O₂+C₈H₁₈→8CO₂+9H₂O).

As such, for example, depending on the concentration of O₂ in the air, astoichiometric air-gasoline mixture may be considered to burn at 14.7:1(air-gasoline) ratio, at which the gasoline burns with no excess air orno oxygen being available after combustion. Hence, a lean mixture mayhave more air (e.g., ratio greater than 14.7:1), and a rich mixture mayhave more fuel (e.g., ratio less than 14.7:1). For instance, maximumpower output may be produced at a rich mixture that may haveair-gasoline of approximately 12.6:1, while best fuel economy may be ata lean air gasoline mixture, which may be at air-gasoline ratio of about15.4:1 or greater. Under some operating conditions, the ratio may beultra lean, such as about 65:1 and/or higher. It should be appreciatedthat ultra lean mixtures may combust at a relatively high temperature(e.g., higher than stoichiometric mixture). In some embodiments, thecontroller may determine a duration for operating the engine and/or oneor more cylinders thereof at an elevated temperature that may resultfrom the combustion of a lean or ultra lean mixture, such as to preventdamaging and/or breaking the engine and/or one or more cylindersthereof. Furthermore, the controller may determine and/or selectinjection of air and/or fuel to produce a suitable mixture to correspondwith a load experienced by the engine and/or to correspond with aprojected load.

For example, lean and/or ultra lean mixtures may be produced when avehicle, such as a car, that is powered by the engine experiences a lowload (e.g., at constant or reducing speeds, a car driving downhill,etc.). The controller may determine to produce a stoichiometric and/orrich mixtures when the load increases or is projected to increase (e.g.,when a car is driving uphill or is projected to drive uphill).

In some instances, the controller may determine to inject a leanair-fuel mixture (e.g., to improve fuel economy). Moreover, for example,in the engine including combustion chambers formed by cylinders andpistons, the controller may selectively and/or continuously modifyair-fuel mixtures injected into any cylinder. For example, thecontroller may produce a more lean combustion in one or some cylindersas compared with other cylinder(s). In some instances, the controllermay produce lean combustion in one or some cylinders and stoichiometricor rich combustion in one or more other cylinders.

Stoichiometric combustion of at least some fuels (e.g., gasoline) mayproduce higher burn temperatures than rich combustion, and leancombustion may produce higher burn temperatures than stoichiometriccombustion. Moreover, under some operating conditions, prolongedstoichiometric and/or lean combustion may damage or break one or moreengine components and/or reduce useful life of the engine. In anembodiment, the controller may determine injection and/or combustioncycles that may maintain stoichiometric and/or lean combustion in one ormore cylinders, while monitoring temperatures changes in the engine, andmay modify combustion parameters in such combustion chambers (e.g.,cylinders) to mitigate or eliminate temperature increase(s) that may beharmful to the engine. For instance, the controller may determine toterminate lean stoichiometric and/or lean combustion in one, some, orall of the cylinders and initiate rich combustion therein. Additionallyor alternatively, the controller may determine to alternate between leanand rich combustion mixtures in one or multiple cylinders (e.g., somecylinders may operate with a lean combustion mixture, while others mayoperate with a rich combustion mixture).

Furthermore, as noted above, the controller may receive input orinformation about the orientation of the crankshaft and/or location(s)of the pistons in the cylinders (e.g., of a reciprocating engine). Undersome operating conditions, the controller may determine to inject fueland/or air into the cylinder(s) at various times and/or multiplelocations of the piston. For example, in lieu of a single injection of aspecific amount of fuel and/or air, the controller may direct fueland/or air injectors to make multiple injections of fuel and/or air(e.g., which may generate the same power output at the crankshaft as thesingle injection of the same, lesser, or greater amount of fuel and/orair). In some instances, multiple injections of fuel and/or air mayimprove air-fuel mixing, combustion of the fuel, etc. Analogously, thecontroller may direct fuel and/or air injectors to make multipleinjections of fuel and air (respectively) into a combustion chamber of arotary engine (e.g., as the rotor thereof rotates).

Moreover, for a reciprocating engine, the controller may direct fueland/or air injectors to inject fuel and/or air, respectively, duringdownward and/or upward movements of the piston. In some embodiments, thecontroller may direct fuel and/or air injectors to inject fuel and/orair during the down stroke of the piston (e.g., in a four stroke cycle,during the intake and/or during power stroke). For example, injectingair and/or fuel during the power stroke may improve ignition of the fueland/or provide additional power. In one or more additional oralternative embodiments, the controller may direct fuel and/or airinjectors to inject fuel and/or air during the exhaust stroke (e.g., ina four stroke cycle), which may aid in evacuating the exhaust gases outof the cylinder.

In some instances, the controller may determine to make multipleinjections of air and fuel to produce stoichiometric and/or leanair-fuel mixtures in the combustion chamber(s) of the engine. Forexample, the controller may determine injection timings at least in partbased on selected and/or predetermined orientations of the output shaft(e.g., orientation of the crankshaft of a reciprocating engine),selected and/or predetermined positions of the piston in the cylinder,combinations of the foregoing, etc. Moreover, the controller maydetermine to make one or more such air and fuel injections that mayproduce stoichiometric and/or lean mixtures, and to make one or more airand fuel injections that may produce rich mixtures (e.g., which mayreduce or minimize temperature increase of the engine during thestoichiometric and/or lean combustion).

In some instances, the controller may determine to operate one or morecylinders of the engine at any even-numbered combustion cycle (e.g.,two-, four- six-, etc.). For example, the controller may determine toinject air and fuel into one, some, or all cylinders on every downstroke of the piston, every second down stroke, every third down stroke,and so on. For instance, the controller may determine to operate some orall cylinders on a two-stroke cycle for a predetermine amount of time tomeet power requirements requested in one or more inputs received by thecontroller and, under some conditions, may determine that subsequent tomeeting such power requirements cylinders may be operated in four-strokecycle.

In some embodiments, the controller may determine to turn off orshutdown one or some of the combustion chambers (e.g., one or some ofthe cylinders). For example, the controller may determine whichcylinder(s) may be turned off to improve fuel efficiency while meetingthe power output requirements. For example, the controller may determineto turn off fuel and/or air injection to one or more cylinders (e.g., tostop combusting fuel in such cylinders). Under some operatingconditions, the controller may also determine to close and/or maintainclosed exhaust valves of the turned off cylinders.

In some instances, a spark may be required to produce combustion of theair-fuel mixture in the cylinder(s). For example, an air-gasolinemixture may be ignited in the cylinder by a spark (e.g., from a fueligniter, such as a spark plug). As such, in one or more embodiments, thecontroller performs or executes an act 230 of determining timing ofspark in one or more combustion chambers (e.g., in the cylinders). Forinstance, for a reciprocating engine, the controller may determine toinject fuel and air at multiple times and/or locations during downwardstroke of a piston. Similarly, the controller may determine one or moretimes for providing a spark in the cylinder, which may correspond withone or more times of fuel and/or air injections (e.g., at approximatelythe same time(s) as the fuel and air is injected; at a selected and/orpredetermined amount of time after injection of air and/or fuel into thecylinder; at selected and/or predetermined locations of the pistonand/or orientation of the crankshaft, which may be based on the inputfrom the encoder; etc.). In any event, the controller may determinesuitable times for providing a spark in the corresponding cylinder(s) tocombust the air-fuel mixture therein.

As described above, generally, piston connector rods that may rotatablyconnect pistons to the crankshaft, and reciprocation of pistons in thecorresponding cylinders may produce rotation of the crankshaft. As such,depending on angular position of the piston connector rod relative tothe crankshaft, downward force on or movement of the piston may producecorresponding torque on and/or rotation of the crankshaft in a clockwiseor counterclockwise direction. For instance, at top dead center (TDC),the connector rod may be parallel to center axis of the cylinder andperpendicular to the crankshaft (e.g., downward force on the piston mayproduce no rotation of the crankshaft). Analogously, when the piston isat a location that is before the TDC (BTDC) or after the TDC (ATDC), theconnection point of the connector rod of the piston may be at anon-perpendicular angle relative to the rotation axis of the crankshaft(e.g., downward force onto the piston may produce correspondingclockwise or counterclockwise rotation of the crankshaft). For example,when the piston is BTDC, force applied to the piston may producecorresponding relative counterclockwise force and/or rotation of thecrankshaft; when the piston is after TDC (ATDC), force applied to thepiston may produce corresponding relative clockwise force and/orrotation of the crankshaft.

As noted above, the controller may receive input from an encoder, andsuch input may identify a relative orientation of the engine'scrankshaft. Furthermore, in some instances, based on the relative radialorientation of the crankshaft, the controller may determine or correlatepositions of the piston(s) in the cylinders (e.g., where each of thepistons is positioned relative to TDC). In some embodiments, thecontroller may start the engine without producing an initial rotation ofthe crankshaft and/or movement of the pistons (e.g., without a starter).For instance, the controller may determine or identify one or morecylinders that have pistons positioned at ATDC and may determine toinject air and/or fuel into such cylinders and to provide a spark intosuch cylinders (where suitable) for igniting air-fuel mixture (e.g., thecontroller may determine or identify the cylinders for providingair-fuel mixture and igniting such mixture to start the engine).

Furthermore, for the cylinders that have pistons at ATDC, the controllermay determine the sequence of injecting air and/or fuel as well as forproviding a spark to ignite the air-fuel mixture (e.g., at leastpartially in response to a received input requesting engine start). Forinstance, the controller may determine to start injection of fuel and/orair into the cylinder that has the piston at a selected and/orpredetermined position or angle relative to the crankshaft (e.g.,nearest to a selected and/or predetermined angle and/or after suchselected and/or predetermined angle). For example, the controller maydetermine to start injection of fuel and air and/or may provide sparkfor igniting the air-fuel mixture in the cylinder that has a piston atleast at ATDC 10 degrees and/or closest to 10 degrees relative to thecrankshaft. The controller may also determine the amount of fuel and airto inject into such cylinders.

In some embodiments, the controller may determine or identify cylindersfor injecting air and/or fuel as well as for igniting the air-fuelmixture to stop and/or reverse rotation of the crankshaft (e.g., atleast partially in response to a received input indicating stoppageand/or reversal of the rotation of the crankshaft). As mentioned above,the controller may receive input that may identify locations of thepistons in the cylinders. For example, the controller may determine oridentify cylinders that have pistons positioned at BTDC (e.g., on pistonup stroke) and may determine the amount of air and/or fuel suitable forproducing a combustion pressure to stop rotation of the crankshaftand/or reverse the rotation thereof. In other words, based on theoperation of the engine and/or one or more received inputs (e.g., RPM ofthe crankshaft, load on the crankshaft, such as external load from amechanism connected to the shaft, location(s) of the pistons in thecylinders at the time of received request to stop or reverse therotation of the crankshaft, etc.), the controller may determine theamount of torque required or suitable to stop and/or reverse rotation.Moreover, in some examples, the controller may determine the amount ofair and fuel to inject into one or more cylinders to produce thedetermined amount of torque for stopping and/or reversing rotation ofthe crankshaft.

As mentioned above, the engine may be included in any number ofengine-powered vehicles (e.g., automobile, watercraft, aircraft, etc.).Hence, for instance, an operator of such vehicle may provide input orrequest at an interface for reversal of the rotation of the movement ofthe vehicle. The controller may subsequently receive the inputindicating a request for reversal of rotation of the crankshaft of theengine, and may determine the amount of air and fuel to inject into thecylinder(s) to produce such reversal as well as may identify thespecific or suitable cylinders for making such injections of air andfuel.

In at least one embodiment, the controller performs or executes an act240 of operating one or more air injectors and/or fuel injections atleast in part based on the determined air-fuel mixture. As mentionedabove, the fuel and/or air may be directly injected into the selectedand/or predetermined cylinders. In other words, the controller maydetermine or identify one or more cylinders for injecting air and fuelas well as igniting the air-fuel mixture in such cylinders; thecontroller may determine the amount of air and/or fuel to inject; thecontroller may determine the sequence (e.g., order of injections of airand/or fuel among the cylinders); the controller may determinecombinations of the foregoing.

In some embodiments, the controller performs or executes an act 250 ofoperating one or more fuel igniters (e.g., spark plugs) at least in partbased on determined timing of the spark (e.g., in act 230). Forinstance, for a reciprocating engine, the controller may determine thetiming of providing the spark in one or more of the cylinders (e.g.,based on the input from the encoder, which may be related to and/or mayidentify orientation of the crankshaft and/or corresponding positions ofthe pistons). Moreover, as described above, the encoder may have anysuitable resolution (e.g., ½ degree or less, etc.); hence, in at leastone embodiment, the controller may operate the fuel igniters withoutadded or intentional delay between receiving the input from the encoderand operating the determined fuel igniter (e.g., only with the delayinherent in signal transmission from the controller to the fuel igniterand/or in computational operations of the controller).

Also, as described above, the controller may determine to inject airand/or fuel at multiple times and/or positions of the piston on the downstroke thereof. Moreover, the controller may operate the fuel and airinjectors to inject air and fuel into the cylinder at such determinedtimes and locations (of the pistons) as well as in the determinedamounts. In at least one embodiment, the controller may operate the fueligniters at multiple selected and/or predetermined times and/orlocations of the piston in the cylinder, which may be related orcorrespond to the times of the controller's operation of the air andfuel injectors.

It should be appreciated that the above described acts 210-250 may beperformed by the controller in any suitable order. Moreover, in someembodiments, one or more of the acts may be omitted and/or substituted.For instance, the engine may operate on any number of suitable fuels(e.g., diesel, hydrogen, propane, etc.) and, under some operatingconditions, the controller may operate or control and engine without aspark (e.g., engine operating on diesel fuel). As such, in someexamples, acts 230 and/or 250 may be omitted.

In some embodiments, to determine the amount of air and fuel to injectinto a cylinder, the controller may be configured or programmed todetermine the air to fuel ratio (AFR) and a suitable volume for thecylinder. For example, as described herein, the controller may beconfigured or programmed to determine the combustion volume; thecontroller may direct one or more air injectors to inject air (or othersuitable oxidant) into the cylinder, to produce the determinedcombustion volume therein. Moreover, the controller may be configured orprogrammed to determine a suitable amount of fuel to inject into thecylinder and may direct fuel injectors to inject the determined amountof fuel (e.g., to produce a suitable AFR in the cylinder). In at leastone embodiment, the controller may be configured or programmed todetermine the amount of air and fuel to inject by determining a suitablecombustion volume and a suitable AFR for one or more operatingconditions (e.g., required or demanded power output).

Additionally or alternatively, the controller may be configured orprogrammed to determine the combustion volume independently of the AFR.For example, the controller may be configured or programmed to determinesuitable AFRs for one or more selected combustion volumes and operatingcondition(s) of the engine. For example, the controller and/or a usermay select a combustion volume for the engine (e.g., user may select theengine to run at a specific combustion volume, such as 0.5 liters, 2.5liters, 3.0 liters, etc.); the controller may be configured orprogrammed to determine the AFRs for the selected combustion volume thatcorrespond to operating conditions of the engine (e.g., desired orselected power output of the engine). Hence, for example, the controllermay be configured or programmed to hold or produce a constant combustionvolume in the cylinder, while modifying the AFR. It should beappreciated that the selected combustion volume for the cylinder may begreater than the actual or nominal volume of the cylinder or less thanthe volume of the cylinder (e.g., the pressure in the cylinder after theinjection of air, and when the cylinder is at the bottom dead center,may be below atmospheric pressure).

In additional or alternative embodiments, the controller may beconfigured or programmed to determine suitable combustion volumes forthe cylinder for a selected AFR. For example, the controller may beconfigured or programmed to hold or maintain a selected AFR whilevarying the combustion volume, such that the engine produces a suitableor selected output. For example, the AFR may be selected based on a smogrestriction or requirement (e.g., smog requirements in somejurisdictions may effectively cap the AFR), based on fuel economyrequirements, etc., and the combustion volume may be selected to such asto produce a selected or desired engine output.

In some embodiments, the controller may be configured or programmed tocalculate the combustion volumes for a selected AFR, to produce aselected or suitable engine power output based on a formula oralgorithm. In at least one embodiment, the controller may be configuredor programmed to determine the AFR based Hopkinson-type curve(s). Forexample, based on a selected distance from a location of detonation orignition of the air-fuel mixture to top of piston and a scaled chargeratio, such as

P=R/W ^(1/3),

where P is the power output of the engine, R is the distance from thelocation of combustion of the air-fuel mixture to the piston, and W isthe energy produced during combustion). Hence, for example, R may begenerally constant (e.g., for a constant RPM of the engine), and thecontroller may be configured or programmed to determine the AFR bycalculating W, or the amount of energy required to produce the selectedor desired output.

Additionally or alternatively, the controller may include and/or may beoperably coupled to a table or database that may include suitable valuesfor the amount of air and fuel to inject for one or more correspondingoperating conditions. For example, the table or database may correlatethe values for the amounts of fuel and air to inject into the cylinderwith each value for combustion volume, AFR and selected power output. Inother words, the table may have (1) air and fuel values for producingsuitable combustion volumes at a selected or constant AFR, to produce aselected power output of the engine, and/or (2) air and fuel values forproducing suitable AFRs for any number of discrete or constantcombustion volumes, to produce a selected power output of the engine.

In some embodiments, the table may be generated based on empirical dataor testing of the various conditions and corresponding engine poweroutputs. For example, the controller may be configured or programmed todirect the air and fuel injectors to produce a constant AFR (e.g., AFRof 14.7:1) and vary or incrementally increase or decrease the combustionvolume (e.g., by increasing the fuel injection with the increase of airinjection in a manner that maintains a constant AFR as the combustionvolume is increased); the controller can measure or receive datacorresponding to the measurements of the engine output to generate atable. Similarly, the controller may be configured or programmed todirect the air and fuel injectors to produce a constant combustionvolume (e.g., any selected combustion volume that can be the same as thecylinder volume, greater, or less than the cylinder volume) and vary theAFR (e.g., by increasing the fuel injection while maintaining airinjection constant); the controller can measure or receive datacorresponding to the measurements of the engine output to generate atable.

In some embodiments, output of the engine may be measured by couplingthe output shaft (e.g., the crankshaft) of the engine to a dynamometer.Additionally or alternatively, a pressure sensor may be suitablypositioned to detect pressure in the cylinder. FIG. 12 is a schematicillustration of a cylinder 15 a that includes a pressure sensor 19 a. Asmentioned above, the cylinder 15 a may be included in any suitableengine that may have any number of configurations and/or any suitablenumber of cylinders.

In the illustrated example, the pressure sensor 19 a is incorporated orincluded in a sparkplug 46 a. In other examples, the pressure sensor maybe positioned at any number of suitable locations. The pressure sensor19 a may be operably coupled to a controller 5 a, such that thecontroller 5 a may receive or detect one or more signals from thepressure sensor 19 a, which may be related to and/or based on thepressure in the cylinder 15 a (e.g., the pressure sensor 19 a may detectthe pressure in the cylinder 15 a and generate or modify a signal thatmay be received at the controller 5 a).

For example, the controller 5 a may continuously or intermittentlymonitor the pressure in the cylinder 15 a. Moreover, the controller 5 amay be configured or programmed to correlate the detected pressure withthe power generated at the output shaft of the engine. It should beappreciated that the pressure in the cylinder 15 a changes during thecycle of the engine. Moreover, as described below, the engine mayinclude one or more additional sensors, such as sensors that mayindicate the stage of the cycle or the position of the piston (e.g., theengine may include one or more encoders coupled to the crankshaft andconnected to the controller 5 a). In at least one embodiment, thecontroller 5 a may correlate the detected pressure in the cylinder withthe position of the piston and/or the stage of the combustion cycle. Forexample, the controller 5 a may be configured or programmed to correlatethe highest pressure, pressure gradient, pressure change, etc., duringthe power stage of the cycle or the down stroke of the piston with thepower output of the engine (e.g., the power generated at the outputshaft of the engine).

Hence, for example, the controller 5 a may be configured or programmedto compare the calculated value(s) and/or the values assigned in thetable for AFR, combustion volume, compression, amount of air, amount offuel, altitude, etc., and power output values. Moreover, as describedabove, controller 5 a may be configured or programmed to determine thesuitable values for the combustion volume and AFR (e.g., suitable valuesfor the amount of air or other suitable oxidant and fuel to inject intothe cylinder), such as described above.

In some embodiments, the controller 5 a may be configured or programmedto determine the fuel type and/or the combustion properties of the fuelbased on the pressure in the cylinder (e.g., during the combustion offuel), as determined by the pressure sensor 19 a. For example, thecontroller 5 a may be calibrated and/or may generate one or more tablesthat include values corresponding to the AFR, combustion volumes,compression ratios, and pressure in the cylinder 5 a based on one ormore known fuels or fuel combinations (e.g., the controller 5 a may beconfigured or programmed to vary amounts of injected air and/or fuel togenerate the tables). Furthermore, the controller 5 a may be configuredor programmed to compare the power output of an unknown or unspecifiedfuel, based on the corresponding amounts of fuel and air injected (e.g.,adjusted for elevation) and corresponding known or expected poweroutputs.

For example, the controller 5 a may be configured or programmed togenerate regression functions or curves based on the followingvariables: amount of air, amount of fuel, altitude, power strokepressure, etc. Furthermore, the controller 5 a may generatetwo-dimensional or three-dimensional curves or regression functionsbased on the known values of the variables; furthermore, based on thegenerated curves and/or regression functions, the controller 5 a maydetermine one or more unknown variable (e.g., to determine the fuel typeor combustion properties thereof). For example, the controller 5 a maymatch two analogous curves, one generated with a known fuel and anotherwith an unidentified fuel, thereby identifying the unidentified fuel.

Hence, for example, the controller 5 a may be configured or programmedto determine the type and/or the combustion properties of the fuel basedon the pressure readings in the cylinder 15 a (e.g., as received fromthe pressure sensor 19 a), the amount of air and fuel injected into thecylinder 15 a, the altitude (or estimated or determined amount orconcentration of oxygen in the injected air), and compression ratio. Asdescribed above, the controller 5 a may be configured or programmed todetermine the amount of air and fuel to inject into the cylinder basedat least in part on the type of fuel and/or the combustion properties ofthe fuel.

It should be appreciated that, at different geographic locations and/oraltitudes, the air may contain different amounts of oxygen therein. Inan embodiment, an oxygen sensor may detect the amount of oxygen in airto adjust the AFR and/or the amount of air injected into the cylinder.In some embodiments, one or more pressure and/or temperatures sensorsmay be suitably positioned to determine the pressure and temperature inthe ambient air outside the engine; based on the ambient pressure andtemperature, the controller 5 a may be configured or programmed todetermine the amount or concentration of oxygen in the air injected intothe cylinder 15 a and may adjust the amount of air and/or fuel based onthe amount of injected oxygen and compression pressure.

In some embodiments, the controller 5 a may be operably coupled to oneor more oxygen and/or air quality intake sensors. For example, asdescribed above, the one or more sensors may be operably connected to orincluded in the intake manifold. In some embodiments, air qualitysensors may be positioned at least partially inside the air intakemanifold or in fluid communication with the air therein. Specifically,the air quality sensors may determine oxygen concentration in the airbeing injected into the cylinder 15 a, contaminants being injected intothe cylinder, etc.

Furthermore, the controller 5 a may be configured or programmed todetermine the amount of air and fuel to inject into the cylinder 15 abased at least in part on the pressure detected by the pressure sensor19 a in the cylinder 15 a. For example, the controller 5 a may beconfigured or programmed to direct the air and/or fuel injector(s) toincrease or decrease the amount of injected air and/or fuel to achieve asuitable or desired pressure in the cylinder 15 a. In some embodiments,a power output may be selected at least in part by a user (e.g., by userdemand, such as for an engine included in a vehicle, where anaccelerator position may correspond to the user demand selection).Hence, for example, the controller 5 a may be configured or programmedto modify the amounts of air and/or fuel injected into the cylinder toproduce a suitable combustion pressure that corresponds to the requestfor a selected power output received by the controller 5 a (e.g., from auser).

Moreover, as described above, as the controller 5 a determines thesuitable amount of air and/or fuel to inject into the cylinder 15 a(e.g., to direct the air and fuel injector(s)), the controller 5 a maydetermine the amount of air and fuel based on a constant combustionvolume or AFR or based on varied combustion volume and AFR (as describedabove), to produce a selected power output or combustion pressure in thecylinder 15 a. Hence, for example, the controller 5 a may direct the airand fuel injector(s) in a manner that incrementally varies (e.g.,increase or decreases by a selected increment amount) the amount of airand/or fuel injected into the cylinder 5 a to produce the suitable orselected output or combustion pressure.

As mentioned above, the controller 5 a may be configured or programmedto operate or direct operation of air and/or fuel injector(s). In someembodiments, the controller 5 a operates or directs operation of the airand/or fuel injector(s) to remain open for selected time duration, suchthat a selected or determined amount of air and/or fuel is injected intothe cylinder 15 a. For example, the controller 5 a may receive one ormore signals from one or more pressure sensors in fluid communicationwith the intake manifold and may direct opening of the air injector(s)for a selected time duration (e.g., based on the pressure of the airbeing injected through the air injector(s), the controller 5 a maydetermine the time duration to maintain the injector(s) open and allowthe air to be injected into the cylinder). Similarly, the controller 5 amay receive one or more signals that correspond to the pressure of thefuel being injected through the fuel injector(s); based on the fuelpressure, the controller 5 a may determine the time duration forinjecting a selected amount of fuel.

That is, the controller 5 a may direct the fuel and/or air injector(s)to open for a selected amount of time to inject a selected amount offuel and/or air into the cylinder. Additionally or alternatively, thecontroller 5 a may determine the suitable pressure for the fuel and/orair flowing to the respective fuel and air injector(s). In someembodiments, the controller 5 a may direct a change in the pressure ofthe fuel and/or air, to produce the respective suitable amounts of airand fuel injection into the cylinder. For example, to increase theamount of air flowing into the cylinder, the controller 5 a may directthe air injector to open for an increased time duration and/or maydirect a compressor to increase the pressure of the air flowing to theair injector(s) (e.g., to increase pressure in the intake manifold).Conversely, to decrease the amount of air flowing into the cylinder, thecontroller 5 a may direct the air injector to open for a decrease timeduration and/or may direct a compressor to increase the pressure of theair flowing to the air injector(s) (e.g., to increase pressure in theintake manifold).

Similarly, to increase the amount of fuel flowing into the cylinder, thecontroller 5 a may direct the fuel injector to open for an increasedtime duration and/or may direct a fuel pump to increase the pressure ofthe fuel flowing to the fuel injector (e.g., to increase pressure in theintake manifold). Furthermore, to decrease the amount of fuel flowinginto the cylinder, the controller 5 a may direct the fuel injector toopen for an increased time duration and/or may direct a fuel pump todecrease the pressure of the fuel flowing to the fuel injector.

Hence, generally, the controller 5 a may direct the fuel pump, the aircompressor, the air injector(s), and the fuel injector(s) in a mannerthat injects a suitable amount of fuel and air (e.g., to produce asuitable combustion volume and AFR, as described above). Moreover, thecontroller 5 a may produce a suitable air and fuel speed inside thecylinder. For example, as the RPM of the engine increases, thecontroller 5 a may direct the fuel pump and/or the air compressor toincrease fuel and air pressure, to produce suitable injection speed. Forexample, the controller 5 a may direct or control the air and fuelinjectors, compressor, and fuel pump, such that the fuel and airinjection is completed when the piston is at a selected or suitableposition in the cylinder (e.g., when the piston is at or near the bottomdead center, when the piston is less than half way, moving from thebottom dead center to the top dead center, etc.). Similarly, when theRPM of the engine decreases, the controller 5 a may direct the fuel pumpand/or the air compressor to decrease fuel and air pressure, to producesuitable injection speed (e.g., such that the fuel and air injection iscompleted when the piston is at a selected or suitable position in thecylinder).

In some embodiments, the controller 5 a may be configured or programmedto increase or decrease the amount and/or flow velocity of air and/orfuel into the cylinder 15 a by operating or controlling any number ofsuitable air and/or fuel injectors. For example, the air and/or fuelinjectors may have a size-variable opening that size of which (e.g., thecross-sectional are of which) may be controlled by one or more signalsfrom the controller 5 a. In an example, the air and/or fuel injector mayhave an orifice and a tapered shaft that may seal the orifice; thecontroller 5 a may direct movement of the tapered shaft relative orificeto effectively change the size of the opening through which the fluid(e.g., are or gas) may flow. Hence, for example, by operating the airand/or fuel injector to change the size of the opening therein, thecontroller 5 a may direct the air and/or fuel injector(s) to inject asuitable amount of air and/or fuel at suitable flow velocities into thecylinder 15 a.

Generally, the controller described herein may include any number ofsuitable computing devices (e.g., engine control units (ECUs) that maybe hardware and/or software programmed and/or operated). Moreover, theacts or steps described herein may be executed by a softwareinstructions stored on the computing device (e.g., in the memory of thecomputing device) and/or by the hardware that is configured to executesuch acts or steps. An example of a suitable computing device isillustrated in FIG. 13. More specifically, FIG. 13 is a block diagram ofa computing device 300 according to an embodiment; the computing device300 may be configured to perform one or more of the processes or actsdescribed above.

For instance, the computing device 300 may include a computer program(e.g., software or hardware coded), which may direct or provideinstructions to various components and/or elements of the computingdevice 300 to perform the acts described above. In an embodiment, thecomputing device may comprise a processor 310, memory 320, a storagedevice 330, an I/O interface 340, a communication interface 350, orcombinations thereof. While FIG. 13 illustrates an exemplary computingdevice 300, the illustrated components are not intended to be limiting.Additional or alternative components may be used in other embodiments.Furthermore, in certain embodiments, a computing device 300 can includefewer components than those shown in FIG. 13.

In some embodiments, processor(s) 310 includes hardware for executinginstructions, such as those making up a computer program. As an exampleand not by way of limitation, to execute instructions, processor(s) 310may retrieve (or fetch) the instructions from an internal register, aninternal cache, memory 320, or a storage device 330 and decode andexecute them. In particular embodiments, processor(s) 310 may includeone or more internal caches for data, instructions, or addresses. As anexample and not by way of limitation, processor(s) 310 may include oneor more instruction caches, one or more data caches, and one or moretranslation lookaside buffers (TLBs). Instructions in the instructioncaches may be copies of instructions in memory 320 or storage 330.

The computing device 300 may include memory 320 coupled to theprocessor(s) 310. The memory 320 may be used for storing data, metadata,programs, or combinations thereof for execution by the processor(s). Thememory 320 may include one or more of volatile and non-volatilememories, such as Random Access Memory (“RAM”), Read Only Memory(“ROM”), a solid state disk (“SSD”), Flash, Phase Change Memory (“PCM”),or other types of data storage. The memory 320 may be internal ordistributed memory.

The computing device 300 may include a storage device 330 that may havestorage for storing data and/or instructions. As an example and not byway of limitation, storage device 330 may comprise a non-transitorystorage medium described above. The storage device 330 may include ahard disk drive (HDD), a floppy disk drive, flash memory, an opticaldisc, a magneto-optical disc, magnetic tape, or a Universal Serial Bus(USB) drive or a combination of two or more of these. Storage device 330may include removable or non-removable (or fixed) media, whereappropriate. Storage device 330 may be internal or external to thecomputing device 300. In some embodiments, storage device 330 isnon-volatile, solid-state memory. Additionally or alternatively, thestorage device 330 may include read-only memory (ROM). Whereappropriate, this ROM may be mask programmed ROM, programmable ROM(PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM),electrically alterable ROM (EAROM), or flash memory or a combination oftwo or more of these.

The computing device 300 also may include one or more input or output(“I/O”) interface(s) 340, which may be provided to allow a user toprovide input to, receive output from, and otherwise transfer data toand from the computing device 300. For example, the I/O interface(s) 340may be coupled to one or more sensors (described above (e.g., pressuresensors, temperature sensors, fuel sensors, etc.)) and/or to one or moreinput device (e.g., a throttle, a user interface, a mouse, keypad or akeyboard, a touch screen, camera, optical scanner, network interface,modem, other known I/O devices or combinations thereof). The touchscreen may be activated with a stylus or a finger.

The I/O interface(s) 340 may include and/or may be coupled one or moredevices for presenting output to a user, including, but not limited to,a graphics engine, a display (e.g., a display screen), one or moreoutput drivers (e.g., display drivers), one or more audio speakers, andone or more audio drivers. In some embodiments, interface(s) 340 may beconfigured to provide graphical data to a display for presentation to auser. The graphical data may be representative of one or more graphicaluser interfaces and/or any other graphical content as may serve aparticular implementation.

The computing device 300 may further include a communication interface350. The communication interface may include hardware, software, orboth. The communication interface 350 may provide one or more interfacesfor communication (such as, for example, packet-based communication)between the computing device and one or more other computing devices 300or one or more networks. As an example and not by way of limitation,communication interface 350 may include a network interface controller(NIC) or network adapter for communicating with an Ethernet or otherwire-based network or a wireless NIC (WNIC) or wireless adapter forcommunicating with a wireless network, such as a WI-FI.

This disclosure contemplates any suitable network and any suitablecommunication interface 350. As an example and not by way of limitation,computing device 300 may communicate with an ad hoc network, a personalarea network (PAN), a local area network (LAN), a wide area network(WAN), a metropolitan area network (MAN), or one or more portions of theInternet or a combination of two or more of these. One or more portionsof one or more of these networks may be wired or wireless. As anexample, computing system 300 may communicate with a wireless PAN (WPAN)(such as, for example, a BLUETOOTH WPAN), a WI-FI network, a WI-MAXnetwork, a cellular telephone network (such as, for example, a GlobalSystem for Mobile Communications (GSM) network), or other suitablewireless network or a combination thereof. Computing device 300 mayinclude any suitable communication interface 350 for any of thesenetworks, where appropriate.

The computing device 300 may further include a bus 360. The bus 360 maycomprise hardware, software, or both that couples components ofcomputing device 300 to each other. As an example and not by way oflimitation, bus 360 may include an Accelerated Graphics Port (AGP) orother graphics bus, an Enhanced Industry Standard Architecture (EISA)bus, a front-side bus (FSB), a HYPERTRANSPORT (HT) interconnect, anIndustry Standard Architecture (ISA) bus, an INFINIBAND interconnect, alow-pin-count (LPC) bus, a memory bus, a Micro Channel Architecture(MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express(PCIe) bus, a serial advanced technology attachment (SATA) bus, a VideoElectronics Standards Association local (VLB) bus, or another suitablebus or a combination thereof.

In some embodiments, a suitable engine control unit (ECU) may be usedand/or programmed to control the elements and/or components of theengine and/or to perform the acts described herein. For example, theEMS-4, which is available from AEM Electronics, may be programmed and/ormay store executable software code that may perform the acts describedherein for a 4-cylinder engine. It should be appreciated that, while insome embodiments, the controller or a computing device may be specialpurpose computer, such as a suitable ECU, in additional or alternativeembodiments, the controller or computing device may be a general purposecomputer.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

What is claimed is:
 1. A combustion system, comprising: an engineincluding: one or more combustion chambers each of which includes one ormore injection ports and an exhaust port; one or more injectors each ofwhich is in communication with a corresponding one of the one or moreinjection ports, each of the one or more injectors configured to injectat least an amount of air into a corresponding one of the one or morecombustion chambers for a combustion reaction that produces a pressureincrease within the corresponding one of the one or more combustionchambers; one or more energy conversion mechanisms each of which ispositioned within in a corresponding one of the one or more combustionchambers and configured to convert the pressure increase in thecorresponding one of the one or more combustion chambers into mechanicalenergy; an output shaft configured to move in response to the mechanicalenergy generated by the one or more energy conversion mechanisms; and atleast one exhaust valve in communication with the exhaust port of eachof the one or more combustion chambers; wherein the engine is devoid ofat least one of a throttle body, a retainer, a cam lobe, a cam shaft, atiming belt, or a shim; and a controller operably coupled to the engineand configured to: determine the amount of the air, at least partiallybased on one or more inputs received by the controller, to inject intoat least one combustion chamber of the one or more combustion chambersthrough the one or more injectors in communication with the at least onecombustion chamber; and actuate the one or more injectors incommunication with the at least one combustion chamber to inject atleast the amount of air into the at least one combustion chamber.
 2. Thecombustion system of claim 1, wherein: the one or more inputs receivedby the controller include one or more operation inputs relating to atleast one of a power output or a revolutions per minute of the outputshaft to be produced by the engine; and the controller is configured todetermine at least the amount of air to inject into the at least onecombustion chamber of the one or more combustion chambers based at leastpartially on at least one of the power output or the revolutions perminute to be produced by the engine.
 3. The combustion system of claim2, wherein the one or more operation inputs include a throttle inputreceived from one or more position sensors, the throttle input relatingto displacement of a throttle pedal.
 4. The combustion system of claim1, wherein: the one or more inputs received by the controller include arequested combustion volume for the engine; and the controller isconfigured to determine at least the amount of air to inject into the atleast one combustion chamber of the one or more combustion chambersbased on the requested combustion volume for the engine.
 5. Thecombustion system of claim 1, wherein: the one or more inputs receivedby the controller include at least one or more operating parameters of avehicle powered by the engine, the one or more operating parametersincluding at least one of a speed of the vehicle, weather conditionsaround the vehicle, or maneuvers of the vehicle; and the controller isconfigured to determine at least the amount of air to inject into the atleast one combustion chamber of the one or more combustion chambersbased at least partially on the one or more operating parameters of thevehicle powered by the engine.
 6. The combustion system of claim 1,wherein: the one or more combustion chambers of the engine include aplurality of cylinders; each of the one or more injectors includes: afuel injector in communication with a fuel injection port of each of theplurality of cylinders; and an air injector in communication with an airinjection port of each of the plurality of cylinders; the engineincludes: a plurality of air lines, each of the plurality of air linesconnected to a corresponding cylinder of the plurality of cylinders atthe air injector associated with the corresponding cylinder; and aplurality of fuel lines, each of the plurality of fuel lines connectedto a corresponding cylinder of the plurality of cylinders at the fuelinjector associated with the corresponding cylinder; and the controlleris configured to: determine the amount of air to inject into each of theplurality of cylinders through the air injector of each of the pluralityof cylinders; determine an amount of fuel to inject into each of theplurality of cylinders through the fuel injector of each of theplurality of cylinders; for each of the plurality of cylinders, actuatethe air injector in communication with the cylinder to inject the amountof air into the cylinder; and for each of the plurality of cylinders,actuate the fuel injector in communication with the cylinder to injectthe amount of fuel into the cylinder.
 7. The combustion system of claim6, wherein the engine includes: an air intake manifold connected to theplurality of air lines and configured to provide the air to the airlines; an air compressor configured to output pressurized air to the airintake manifold; and at least one air sensor operably coupled to thecontroller and configured to detect an air pressure of the air betweenthe air compressor and the air intake manifold.
 8. The combustion systemof claim 7, wherein: the one or more inputs received by the controllerinclude an air pressure input received from the at least one air sensor;and the controller is configured to determine the amount of air and theamount of fuel to inject into the at least one combustion chamber of theone or more combustion chambers based on the air pressure input receivedfrom the at least one air sensor.
 9. The combustion system of claim 7,wherein: the at least one sensor is configured to determine at least oneof a type of oxidant in the one or more lines or a concentration ofoxygen present in the air between the air compressor and the air intakemanifold; the one or more inputs received by the controller include anair input related to at least one of the type of oxidant or theconcentration of oxygen present in the air in the one or more air lines,as received from the at least one air sensor; and the controller isconfigured to determine the amount of air and the amount of fuel toinject into the at least one combustion chamber of the one or morecombustion chambers based on at least one of the one the type of oxidantor the concentration of oxygen present in the air in the one or more airlines.
 10. The combustion system of claim 7, wherein the engine includesan air pressure regulator configured to regulate an air pressure betweenthe air compressor and the air intake manifold, wherein: the at leastone air sensor includes: a first air pressure sensor operably coupled tothe controller and positioned between the air compressor and the airpressure regulator, the first air pressure sensor configured to detectan output air pressure of the air compressor; and a second air pressuresensor operably coupled to the controller and positioned between the airpressure regulator and the air intake manifold, the second air pressuresensor configured to determine an air pressure in the air intakemanifold.
 11. The combustion system of claim 6, wherein: each of the oneor more injectors includes one or more air injectors; each and every airport of the engine is coupled to a corresponding one of the one or moreair injectors; and for each cylinder of the plurality of cylinders, theair injected into the cylinder through the air injector is unobstructedbetween the air injector and the cylinder.
 12. The combustion system ofclaim 11, wherein, for each cylinder of the plurality of cylinders, theair injector is coupled directly to the air injection port of thecylinder.
 13. The combustion system of claim 6, further comprising: aplurality of fuel sensors operably coupled to the controller, at leastone of the plurality of fuel sensors associated with a corresponding oneof the plurality of fuel lines and configured to determine a type offuel to be injected into a corresponding one or the plurality ofcylinders through the fuel line; wherein the one or more inputs receivedby the controller include a fuel type input received from the at leastone sensor of the plurality of sensors; and wherein the controller isconfigured to determine the amount of air and the amount of fuel toinject into the at least one combustion chamber of the one or morecombustion chambers based on the fuel type input received from the atleast one sensor.
 14. The combustion system of claim 6, wherein, basedon the one or more inputs received by the controller, at least one ofthe amount of fuel or the amount of air determined by the controller toinject into a first cylinder of the plurality of cylinders is differentthan at least one of the amount of fuel or the amount of determined bythe controller to inject into a second cylinder of the plurality ofcylinders.
 15. The combustion system of claim 1, wherein each of the oneor more injectors is configured to inject both the amount of air and anamount of fuel into the corresponding one of the one or more combustionchambers.
 16. The combustion system of claim 13, wherein each of the oneor more injectors is configured inject a pre-mixture of both the amountof air and an amount of fuel into the corresponding one of the one ormore combustion chambers.
 17. The combustion system of claim 1 whereineach of the one or more injectors is configured to inject at least theamount of air into the corresponding one of the one or more combustionchambers for the combustion reaction without the aid of air provided byan air intake stroke from the engine.
 18. A method of controllingcombustion of a combustion engine, the method comprising: with acontroller operably coupled to the combustion engine, receiving one ormore inputs relating to an operating parameter of the combustion engine;with the controller, determining, at least partially based on the one ormore inputs, at least an amount of air to inject into at least some ofone or more combustion chambers in the combustion engine through atleast one injector associated with at least one injection port of thecombustion chamber, the combustion engine being devoid of a throttlebody, a retainer, a cam lobe, a cam shaft, a timing belt, or a shim; andwith the controller, actuating the at least one injector of the at leastsome of the one or more combustion chambers to inject at least theamount of air determined for the at least some of the one or morecombustion chambers.
 19. The method of claim 18, wherein determining atleast an amount of air to inject into at least some of one or morecombustion chambers in the combustion engine through at least oneinjector associated with at least one injection port of the combustionchamber includes: determining, at least partially based on at least oneof a power output or the revolutions per minute to be produced by theengine, at least the amount of air to inject into at least some of oneor more combustion chambers in the combustion engine through the atleast one injector associated with the at least one injection port ofthe combustion chamber.
 20. The method of claim 18, wherein: receivingone or more inputs relating to an operating parameter of the combustionengine includes receiving, at the controller, a throttle input from athrottle position sensor relating to displacement of a throttle pedal;and determining at least an amount of air to inject into at least someof one or more combustion chambers in the combustion engine through atleast one injector associated with at least one injection port of thecombustion chamber includes determining, at least partially based on thethrottle input, at least the amount of air to inject into at least someof one or more combustion chambers in the combustion engine through theat least one injector associated with the at least one injection port ofthe combustion chamber.
 21. The method of claim 17, wherein: receivingone or more inputs relating to an operating parameter of the combustionengine includes receiving, at the controller, a requested combustionvolume for the combustion engine; and determining at least an amount ofair to inject into at least some of one or more combustion chambers inthe combustion engine through at least one injector associated with atleast one injection port of the combustion chamber includes determining,at least partially based on the requested combustion volume for thecombustion engine, at least the amount of air to inject into at leastsome of one or more combustion chambers in the combustion engine throughthe at least one injector associated with the at least one injectionport of the combustion chamber.
 22. The method of claim 18, wherein:receiving one or more inputs relating to an operating parameter of thecombustion engine includes receiving one or more operating parameters ofa vehicle powered by the engine, the one or more operating parametersincluding at least one of a speed of the vehicle, weather conditionsaround the vehicle, or maneuvers of the vehicle; and determining atleast an amount of air to inject into at least some of one or morecombustion chambers in the combustion engine through at least oneinjector associated with at least one injection port of the combustionchamber includes determining, at least partially based on the one ormore operating parameters of the vehicle powered by the engine, theamount of air to inject into at least some of one or more combustionchambers in the combustion engine through the at least one injectorassociated with the at least one injection port of the combustionchamber.
 23. The method of claim 18, further comprising determining,with at least one air sensor operably coupled to the controller, an airpressure of air between an air intake manifold connected to one or moreair lines and an air compressor, the one or more air lines beingconnected to a corresponding combustion chamber of the one or morecombustion chambers through the at least one injector, wherein:receiving one or more inputs relating to an operating parameter of thecombustion engine includes receiving, from the at least one air sensor,the air pressure of the air between the air intake manifold and the aircompressor; and determining at least an amount of air to inject into atleast some of one or more combustion chambers in the combustion enginethrough at least one injector associated with at least one injectionport of the combustion chamber includes determining, at least partiallybased on the air pressure of the air between the air intake manifold andthe air compressor, at least the amount of air to inject into at leastsome of one or more combustion chambers in the combustion engine throughthe at least one injector associated with the at least one injectionport of the combustion chamber.
 24. The method of claim 18, furthercomprising detecting, with an air sensor, at least one of a type ofoxidant or a concentration of oxygen present in the air between an aircompressor and an air intake manifold, wherein: the air intake manifoldprovides the air to the at least one injector of each combustion chamberof the one or more combustion chambers through one or more air lines;receiving one or more inputs relating to an operating parameter of thecombustion engine includes receiving, from the air sensor, at least oneof the type of oxidant or the concentration of oxygen present in the airbetween the air compressor and the air intake manifold; and determiningat least an amount of air to inject into at least some of one or morecombustion chambers in the combustion engine through at least oneinjector associated with at least one injection port of the combustionchamber includes determining, at least partially based on at least oneof the type of oxidant or the concentration of oxygen present in the airbetween the air compressor and the air intake manifold, the amount ofair to inject into at least some of one or more combustion chambers inthe combustion engine through the at least one injector associated withthe at least one injection port of the combustion chamber.
 25. Themethod of claim 18, further comprising determining, with one or morefuel sensors operably coupled to the controller, a type of fuel to beinjected into the one or more combustion chambers, wherein: receivingone or more inputs relating to an operating parameter of the combustionengine includes receiving, from the one or more fuel sensors, the typeof fuel to be injected into the one or more combustion chamber; anddetermining at least an amount of air to inject into at least some ofone or more combustion chambers in the combustion engine through atleast one injector associated with at least one injection port of thecombustion chamber includes determining, at least partially based on thetype of fuel to be injected into the one or more combustion chambers,the amount of air to inject into at least some of one or more combustionchambers in the combustion engine through the at least one injectorassociated with the at least one injection port of the combustionchamber.
 26. The method of claim 18, wherein: determining, at leastpartially based on the one or more inputs, at least an amount of air toinject into at least some of one or more combustion chambers in thecombustion engine through at least one injector associated with at leastone injection port of the combustion chamber includes: determining, atleast partially based on the one or more inputs, the amount of air andan amount of fuel to inject into at least some of the one or morecombustion chambers through at least one injector associated with the atleast one injection port of the combustion chamber; and actuating the atleast one injector of the at least some of the one or more combustionchambers to inject at least the amount of air determined for the atleast some of the one or more combustion chambers includes: actuatingthe at least one injector of the at least some of the one or morecombustion chambers to inject the amount of air and the amount of fueldetermined for the at least some of the one or more combustion chambers.27. The method of claim 26, wherein: the one or more combustion chambersinclude a plurality of combustion chambers; for each of the plurality ofcombustion chambers, the at least one injector associate with at leastone injection port of the combustion chamber includes an air injectorassociated with an air injection port for the combustion chamber and afuel injector associated with a fuel injection port for the combustionchamber; determining, at least partially based on the one or moreinputs, the amount of air and an amount of fuel to inject into at leastsome of the one or more combustion chambers through at least oneinjector associated with the at least one injection port of thecombustion chamber includes: determining, at least partially based onthe one or more inputs, the amount of air to inject into each of theplurality of combustion chambers through the air injector associatedwith the combustion chamber; and determining, at least partially basedon the one or more inputs, the amount of fuel to inject into each of theplurality of combustion chambers through the fuel injector associatedwith the combustion chamber; and actuating the at least one injector ofthe at least some of the one or more combustion chambers to inject theamount of air and the amount of fuel determined for the at least some ofthe one or more combustion chambers includes: actuating the air injectorof each of the plurality of combustion chambers to inject the amount ofair determined for the combustion chamber; and actuating the fuelinjector of each of the plurality of combustion chambers to inject theamount of fuel determined for the combustion chamber.
 28. The method ofclaim 26, wherein actuating the air injector of each of the plurality ofcombustion chambers to inject the amount of air determined for thecombustion chamber includes: actuating the air injector of each of theplurality of combustion chambers to inject the amount of air determinedfor the combustion chamber directly into the combustion chamber, the airbeing unobstructed between the air injector and the cylinder and the airinjector being attached directly to the air port of the cylinder,wherein each and every airport of the combustion engine is coupled to anair injector.
 29. The method of claim 26, wherein: determining, at leastpartially based on the one or more inputs, the amount of air to injectinto each of the plurality of combustion chambers through the airinjector associated with the combustion chamber includes: determining atleast partially based on the one or more inputs, a first amount of airto inject into a first combustion chamber of the plurality of combustionchambers through the air injector associated with the first combustionchamber; and determining at least partially based on the one or moreinputs, a second amount of air to inject into a second combustionchamber of the plurality of combustion chambers through the air injectorassociated with the second combustion chamber, the second amount of airbeing different than the first amount air; and actuating the airinjector of each of the plurality of combustion chambers to inject theamount of air determined for the combustion chamber includes: actuatingthe air injector associated with the first combustion chamber to injectthe first amount of air determined for the first combustion chamber; andactuating the air injector associated with the second combustion chamberto inject the second amount of air determined for the second combustionchamber.